Used Atlas Copco Screw Compressor Compact Unit for sale (38,617)

Condition: used, Year of construction: 2004, Compressor type: Oil-injected rotary screw compressor with integrated refrigerant dryer Motor power: 15 kW (20 HP) Power supply: 380 V / 50 Hz Operating pressure: 7.5 bar Free Air Delivery (FAD): 798 m³/h (approximately 13.3 m³/min) Noise level: 68 dB(A) Tank capacity: 400 liters Dimensions (L × W × H): 1,000 × 660 × 1,400 mm Weight: 450 kg Cooling: Air-cooled Integrated dryer: Yes Podjwgca Tepfx Amyogp Control system: Elektronikon®

Condition: excellent (used), Year of construction: 2004, operating hours: 114,000 h, overall weight: 4,400 kg, power: 250 kW (339.91 HP), volume flow: 2.802 m³/h, operating pressure: 10 bar, Regularly serviced, in excellent condition. Atlas Copco ZR250 Screw compressor, 10bar 46m3/min Oil-free, water-cooled. MD600 with adsorption dryer Compressor: Manufacturer: Atlas Copco Type: ZR 250 year of manufacture. 2004 loaded operating hours 114,000 Max. operating pressure: 10bar single-stage drive Cooling water consumption 3.7 liters/s Air delivery: 43.6m3/min Water cooled Oil free Power: 250 kW Mains voltage: 400v 50Hz 445A Psdjrp D Uxepfx Amyegp Last service: September 2023 Adsorption dryer, water-cooled Manufacturer: Atlas Copco Type: MD 600 W Year of construction: 2004 Max. operating pressure: 10.5 bar Empty volume: 350 liters machine dimensions: length: 3000mm width: 1600mm height: 2000mm weight: 4400 kg

Condition: good (used), Year of construction: 1998, operating hours: 10,300 h, overall weight: 475 kg, fuel type: electric, volume flow: 186 m³/h, operating pressure: 10 bar, pressure (max.): 10 bar, 22kw 3.1m3/min ATLAS COPCO GA22 screw compressor Continuously serviced and maintained 22kw screw compressor for sale. Manufacturer: Atlas Copco GA22 SP operating hours: 10350 Year of manufacture: 1999 Capacity: 3.1 M3/minute, pressure: 10 bar Power 22kw main engine speed: 3,000/min Net weight: 405 Kg Dimensions: mm (LxWxH) Noise level: 66 dB Pedpfxetxpd Io Amyjgp service booklet, circuit diagram.

Condition: excellent (used), - 30kW engine - built-in dryer Pgsdpfxswlcq Ne Amyep - Max. working pressure 7.5 bar

Condition: good (used), Year of construction: 2019, functionality: fully functional, power: 382 kW (519.37 HP), Description: Screw compressor ZR315VSD Characteristics: Capacity 8.60 bar Psdpevyq Rnsfx Amyegp Power 382 kW Voltage 400 V or 500 V Running hours at last maintenance: 7270

Condition: good (used), Year of construction: 2023, machine/vehicle number: 231293, Offer 25452 Pgodpox I Izrsfx Amyjp Technical data: - Operating hours: 754 h - Working pressure: up to 13 bar - Delivery rate: 860 l/min - Drive: 400 V / 7.5 kW - Galvanised air receiver: 500 l - Integrated dryer RENNER Type RKT + 0065 - Automatic condensate drain - Required space: approx. W 650 x H 1650 x D 1400 mm - Weight: approx. 350 kg

Condition: good (used), Year of construction: 2004, machine/vehicle number: A II 151768, Offer 25979 - Operating hours 16550 h - Operating pressure 10 bar - Delivery rate 15.9 l/s - Drive 400 V / 7.5 kW - Motor speed 3000 rpm - Air tank 250 L - Required space approx. W 700 x H 1830 x D 1050 mm - Weight approx. 250 kg Psdswrcq Njpfx Amysgp

Condition: new, volume flow: 0.79 m³/h, Atlas Copco G5FF 500 l screw compressor, NEW, with refrigerant dryer. Specifications: Psdpfxjg Tzvxo Amyogp • Condition – New • Manufacturer – Atlas Copco • Capacity – 790 l/min • Main motor power – 5.5 kW • Tank – 500 l • Maximum working pressure – 10.0 atm • Built-in refrigerant dryer • Electronic adjustment of compressor operating parameters • Soundproofed enclosure (only 65 dB) • Complies with CE standards • Weight – 221 kg Additional information: • Manufacturer's warranty can be obtained after commissioning by an authorized Atlas Copco service center. • Operating manual in Polish. • Available within 7-10 business days.

Condition: good (used), functionality: fully functional, power: 250 kW (339.91 HP), Description: Screw compressor ZR 4-52 with drum dryer Pedpfsvyrlasx Amyegp Characteristics: Capacity 8.00 bar Power 250 kW Voltage 500 V Air flow rate l/min 634 Running hours at last maintenance: 50307

Condition: good (used), functionality: fully functional, Description: Screw compressor with drum dryer ZR 250 1997 Characteristics: Podpfxsvyrtde Amysgp Capacity 7.50 bar Power 245 kW Voltage 500 V

Condition: like new (used), GA (W) VSDs (Variable Speed Drive) are single-stage, oil-injected, electric motor-driven, stationary screw compressors. The cooling system is equipped with an air cooler and an oil cooler. GA VSD are air-cooled compressors; cooling air is provided by a fan. Main features: - Maximum air inlet temperature: 40°C. - Maximum cooling water outlet temperature: 50°C Pgedpfx Amewxwxzjyjp - Temperature of the air leaving the outlet valve approx.: 30°C - Approximate oil capacity: 17.9 L

Condition: good (used), functionality: fully functional, Description: Screw compressor ZR 250 Podjvyrq Ajpfx Amyegp 1998 Characteristics: Capacity 7.50 bar Power 245 kW Voltage 500 V

Condition: good (used), Year of construction: 2001, functionality: fully functional, power: 305 kW (414.68 HP), Description: Screw compressor with drum dryer ZR315VSD Pgsdovyq Tpepfx Amyjp Characteristics: Capacity 8.60 bar Power 305 kW Voltage 500 V Running hours at last maintenance: 46383

Condition: good (used), Year of construction: 2015, Atlas Copco Oil Free Screw Compressor with built-in Air Dryer Model SF2+FF 7.75 bar / 112 PSI Year 2015 Pjdpfjy Iplfox Amysgp 400 volts three phase, 2.2 KW / 3 HP, 2885 RPM 8.9 CFM / 4.21 lts/s Very little use Ex Pharma Facility

Condition: used, color: red, Year of construction: 1981, operating hours: 4,391 h, Pressure: 11 bar Tank pressure: 11 bar Pgodsx S Nxaspfx Amyop

Condition: new, Year of construction: 2026, The THEOR 20 screw compressor with a refrigerated compressed air dryer. The CORMAK THEOR series screw compressor, manufactured by the Polish brand CORMAK, represents the latest solutions used in pneumatics combined with high-quality materials and components. Low operating costs, ease of use, ergonomic and durable construction, and high efficiency guarantee effective and trouble-free operation. CORMAK screw compressors are synonymous with innovation and reliability, designed for the most demanding applications. Innovative design: Our compressors are based on advanced engineering and European precision manufacturing. The robust construction, enhanced with modern components, ensures long-lasting and reliable operation in all conditions. Integrated refrigerated dryer: The COMPACT version with an integrated dryer saves space and provides a complete all-in-one solution. The built-in refrigerated dryer ensures dry and clean air, protecting your installation from corrosion and damage. Quiet operation and comfort: Designed with attention to detail, our compressors feature exceptionally low noise levels. Effective soundproofing and vibration reduction systems provide a comfortable working environment, improving operator concentration and well-being. Intelligent control: The intuitive MAM series electronic control panel serves as the command center of your compressor. It enables precise parameter monitoring, maintenance scheduling, and quick diagnostics, ensuring stability and protection of key components. Adaptation to your needs: We understand that every application is unique. CORMAK compressors can be configured with additional air treatment systems, allowing perfect adaptation to the specific requirements of your industry. Dynamic working pressure: Automatic pressure regulation ensures that the compressor delivers exactly as much compressed air as needed at any given moment, maximizing energy efficiency and minimizing losses. Sustainable development: We focus on environmentally friendly solutions. The energy-saving technologies used in our compressors not only reduce your operating costs but also minimize environmental impact, while the heat recovery option allows maximum energy utilization. Technical Specifications Parameter Value Motor power 15 kW Voltage 400V / 50Hz Capacity at 0–6 bar 2100 L/min Capacity at 6 bar 2000 L/min Capacity at 8 bar 1700 L/min Capacity at 10 bar 1600 L/min Outlet connection diameter (G) G1" Pgjdpfxey Rpmnj Amyjp Dimensions 1550 × 740 × 1180 mm Weight 500 kg

Condition: new, Year of construction: 2026, The screw compressor of the Polish brand CORMAK, the THEOR H1515.8 COMPACT series, with an integrated dryer is the most modern solutions used in pneumatics in combination with the use of high-quality materials and components. Low operating costs, ease of use, ergonomic and solid construction as well as high efficiency of the device guarantee effective and trouble-free operation. Key benefits: strong, compact design of a screw compressor from a European manufacturer automation based on modern and quality-tested components to ensure safe and effective work a specially designed cooler ensures optimal working conditions even when the device is heavily loaded connection of the radiator with the module through good quality hydraulic hoses the technology used allows for significant energy savings special air outlet design for more efficient work Pgjdpfxsmrmy Aj Amyep a powerful and robust pump is installed in the compressor unique filtration system with triple separation for effective work the compressor uses a reliable and reliable solution, which is a direct drive transmission system between the engine and the screw mechanism (via the so-called claw clutch), which ensures: high effective efficiency; more effective leveling of vibrations low noise of the screw compressor thanks to a specially designed soundproof housing (sound insulation boards) electronic control from the MAM series allows you to set parameters, including: intervals between service inspections, power failure alarms, phase direction changes, phase loss, overheating. Possibility to buy additional cylinders. Technical parameters: Compressor Engine power 15kW Dimensions 1550x750x1200mm Weight 500kg Exhaust thread G 3/4" General parameters Capacity at 0-6 bar 1700L/min Capacity at 6 bar 1650L/min Capacity at 8 bar 1500L/min Capacity at 10 bar 1500L/min Capacity at 12 bar 1350L/min Capacity at 14 bar 1350L/min The price is a net price. Price does not include shipping costs. For more information, please contact us by phone or e-mail. We invite you to familiarize yourself with the offer on our website.

Condition: new, Year of construction: 2026, The screw compressor of the Polish brand CORMAK, the THEOR H1520 COMPACT series, with an integrated dryer is the most modern solutions used in pneumatics in combination with the use of high-quality materials and components. Low operating costs, ease of use, ergonomic and solid construction as well as high efficiency of the device guarantee effective and trouble-free operation. Key benefits: strong, compact design of a screw compressor from a European manufacturer automation based on modern and quality-tested components to ensure safe and effective work a specially designed cooler ensures optimal working conditions even when the device is heavily loaded connection of the radiator with the module through good quality hydraulic hoses the technology used allows for significant energy savings special air outlet design for more efficient work a powerful and robust pump is installed in the compressor unique filtration system with triple separation for effective work the compressor uses a reliable and reliable solution, which is a direct drive transmission system between the engine and the screw mechanism (via the so-called claw clutch), which ensures: high effective efficiency; more effective leveling of vibrations low noise of the screw compressor thanks to a specially designed soundproof housing (sound insulation boards) electronic control from the MAM series allows you to set parameters, including: intervals between service inspections, power failure alarms, phase direction changes, phase loss, overheating. Possibility to buy additional cylinders. Technical parameters: Compressor Engine power 15kW Dimensions 1550x750x1200mm Weight 500kg Exhaust thread G 3/4" General parameters Capacity at 0-6 bar 1350L/min Capacity at 6 bar 1350L/min Capacity at 8 bar 1250L/min Capacity at 10 bar 1250L/min Capacity at 12 bar 1150L/min Capacity at 14 bar 1150L/min Capacity at 16 bar 1050L/min Capacity at 18 bar 930L/min Capacity at 20 bar 930L/min The price is a net price. Price does not include shipping costs. For more information, please contact us by phone or e-mail. We invite you to familiarize yourself with the offer on our website. Pgsdpsmrmx Tefx Amyop

Condition: new, Year of construction: 2026, Are you looking for a professional solution to power pneumatic tools in a workshop, paint shop, or small production line? The CORMAK LUFT 700 screw compressor is the perfect choice. With a 5.5 kW motor and an impressive actual air delivery of up to 690 l/min, it ensures a constant supply of compressed air required for the efficient operation of impact wrenches, blow guns, spray painting equipment, and other pneumatic tools. This model is designed for continuous operation, making it ideal for demanding applications such as tire service centers, smaller automotive workshops, and small manufacturing facilities. Investing in a CORMAK screw compressor means a significant improvement in working comfort – say goodbye to noisy piston compressors and enjoy quieter and more stable operation. The LUFT 700 features a direct-drive system, providing significantly higher efficiency and lower power losses compared to belt-driven models. This innovative solution guarantees optimal utilization of motor power, resulting in higher performance with lower energy consumption. The maximum pressure generated by this screw compressor is 10 bar. Full control over operating parameters is provided by the intuitive MAM-series electronic control panel, giving you access to key compressor information and increasing flexibility and process control. Are you looking for solutions that exceed market standards? CORMAK screw compressors are synonymous with innovation and reliability, designed for the most demanding applications. The combination of the proven reliability of an induction motor with intelligent control makes this screw compressor an extremely efficient, economical, and flexible source of compressed air, perfectly suited to the dynamic needs of modern industry. Podpfxsza Apto Amysgp High-quality CORMAK screw compressors, such as the LUFT 700 model, are based on technologically advanced screw airends that determine their efficiency and reliability. By combining proven engineering solutions with innovation, CORMAK ensures that every airend is refined down to the smallest detail to withstand even the most intensive operating conditions. In CORMAK screw compressors, such as the LUFT 700, a key component ensuring reliability and optimized operation is the advanced MAM-series control panel. Designed for efficient compressed air system management, this controller enables continuous monitoring and rapid response to all operating parameters. TECHNICAL SPECIFICATIONS Motor power: 5.5 kW Power supply: 400V / 50Hz Air delivery at 0–6 bar: 690 L/min Air delivery at 6 bar: 650 L/min Air delivery at 8 bar: 650 L/min Air delivery at 10 bar: 630 L/min Outlet connection (G): 1/2" Dimensions: 1445 × 610 × 1410 mm Weight: 200 kg

Condition: new, Year of construction: 2026, CORMAK LUFT 700 VSD+PM Compact Screw Compressor with Dryer – Compact Package for Demanding Applications – ENERGY SAVER SET INCLUDES: LUFT 700 VSD+PM COMPACT screw compressor with dryer Horizontal compressed air tank – 500 L Key Features of the Energy Saver Series 1. Permanent Magnet (PM) Motor Technology Most compressors in the Energy Saver series use permanent magnet motors. Compared to standard induction motors, they: Achieve efficiency levels of IE4 or even IE5 Maintain high performance even at very low speeds (standard motors lose efficiency outside their nominal range) Are smaller, lighter, and generate less heat 2. Advanced VSD Inverter Control Pgsdpfjycg Rysx Amyep The heart of the Energy Saver line is the frequency inverter (VSD). Adaptation to demand: The compressor does not operate on an "all-or-nothing" principle (load/unload). If your system requires only 30% capacity, the compressor reduces speed, consuming proportionally less energy. Eliminates idle running: Traditional compressors often run for several minutes after the tank is full, consuming about 25–30% of nominal power without producing air. Energy Saver models nearly eliminate this wasteful process. 3. Soft Start Thanks to the inverter, these units start smoothly from 0 Hz. This means no sudden current surges during startup, which: Saves the electrical installation in the facility Allows frequent start/stop cycles without overheating the windings 4. Real Energy Savings In practice, the Energy Saver series can reduce electricity costs by 30% to 50% compared to traditional fixed-speed compressors. Additionally, the system maintains very stable pressure in the network (with accuracy up to 0.1 bar), which is crucial for precision devices such as laser cutters. Longer service life: No sudden pressure and temperature spikes prolong the screw stage life. Technical Specifications Motor power: 5.5 kW / 7.5 HP Voltage: 400V / 50Hz Air delivery at 0–6 bar: avg. 690 L/min Air delivery at 6 bar: 690 L/min Air delivery at 8 bar: 650 L/min Air delivery at 10 bar: 650 L/min Outlet connection (G): 1/2" Dimensions: 1840 × 640 × 1470 mm Weight: 320 kg

Condition: new, Year of construction: 2026, functionality: fully functional, Set containing LUFT 700 screw compressor, N10S refrigeration air dryer and compressed air tank with a capacity of 500l. The screw compressor of the Polish brand CORMAK, the LUFT series, is the most modern solutions used in pneumatics in combination with the use of high-quality materials and components. Low operating costs, ease of use, ergonomic and solid construction as well as high efficiency of the device guarantee effective and trouble-free operation. Additional double filtration on the dehumidifier! KIT INCLUDES: LUFT 700 COMPRESSOR REFRIGERATION AIR DRYER N10S 500L TANK Technical parameters LUFT 700 COMPACT Compressor Engine power 5.5kW Dehumidifier Pgjdpfsrh E Erjx Amysp Engine power 0.29kW General parameters Capacity at 0-6 bar 680 lpm Capacity at 6 bar 650L/min Capacity at 8 bar 650 lpm Capacity at 10 bar 620 lpm Outlet G3/4" Overall dimensions 1250 x 600 x 895 mm Weight 380 kg The price is a net price. Price does not include shipping costs. For more information, please contact us by phone or e-mail. We invite you to familiarize yourself with the offer on our website.

Condition: new, Year of construction: 2026, A set containing THEOR 20 INVERTER screw compressor, N20S refrigeration air dryer. The screw compressor of the Polish brand CORMAK THEOR series is the most modern solutions used in pneumatics in combination with the use of high-quality materials and components. Low operating costs, ease of use, ergonomic and solid construction as well as high efficiency of the device guarantee effective and trouble-free operation. Additional double filtration on the dehumidifier! KIT INCLUDES: THEOR 20 COMPRESSOR with inverter (version equipped with inverter) REFRIGERATION AIR DRYER N20S The set does not include a tank! Possibility to buy additional cylinders THEOR 20 COMPACT technical parameters Compressor Engine power 15kW Dehumidifier Engine power 0.69kW General parameters Capacity at 6 bar 1800 lpm Capacity at 8 bar 1700 l/min Podpomqlqdsfx Amyjgp Capacity at 10 bar 1600 l/min Departure G3/4" The price is a net price. Price does not include shipping costs. For more information, please contact us by phone or e-mail. We invite you to familiarize yourself with the offer on our website.

Condition: new, Year of construction: 2026, CORMAK LUFT 1500 VSD+PM Compact screw compressor with dryer – compact set for demanding applications – ENERGY SAVER SET INCLUDES: LUFT 1500 VSD+PM COMPACT screw compressor with dryer. Horizontal compressed air receiver 500 L. Key features that distinguish these models: 1. Permanent Magnet (PM) Motor Technology Most Energy Saver compressors use Permanent Magnet motors. Unlike standard induction motors: They achieve efficiency levels compliant with IE4 or even IE5 standards. They maintain high efficiency even at very low speeds, where standard motors lose performance. They are smaller, lighter and generate less heat. 2. Advanced Inverter Control (VSD) The core of the Energy Saver line is a frequency converter (inverter). Demand matching: The compressor does not operate on an “all-or-nothing” basis. If your system requires only 30% capacity, it reduces speed accordingly, consuming proportionally less energy. Pgodsychbaopfx Amyop Elimination of idle operation: Conventional compressors often run unloaded for several minutes after filling the tank, consuming around 25–30% of rated power without producing air. Energy Saver models virtually eliminate this loss. 3. Soft Start Thanks to the inverter, these units start smoothly from 0 Hz, eliminating current surges at start-up, which: Protects the plant’s electrical installation. Allows frequent start-stops without overheating the windings. 4. Real Savings In practice, Energy Saver technology reduces electricity bills by 30% to 50% compared with fixed-speed compressors. It also maintains very stable network pressure (within 0.1 bar), essential for precision equipment such as laser cutters. Extended service life: Smooth pressure and temperature changes prolong screw element life. Technical Parameters Motor power 11 kW / 15 HP Voltage 400V / 50Hz Output 0–6 bar 1620 L/min Output at 6 bar 1580 L/min Output at 8 bar 1350 L/min Output at 10 bar 1230 L/min Outlet connection (G) 1" Dimensions 1600 × 740 × 1750 mm Weight 500 kg

Condition: new, Year of construction: 2026, functionality: fully functional, CORMAK LUFT 1000 VSD+PM Compact Screw Compressor with Dryer – Compact Set for Demanding Applications – ENERGY SAVER SET INCLUDES: Pgedpeycg Ufefx Amyep LUFT 1000 VSD+PM COMPACT screw compressor with dryer Horizontal compressed air tank – 500 L Key Features That Distinguish These Models 1. Permanent Magnet (PM) Motor Technology Most compressors in the Energy Saver series use permanent magnet motors. Compared to standard induction motors, they: Achieve efficiency levels compliant with IE4 or even IE5 standards Maintain high efficiency even at very low rotational speeds (standard motors lose efficiency outside their nominal range) Are smaller, lighter, and generate less heat 2. Advanced Variable Speed Drive (VSD) Control The core of the Energy Saver line is the frequency inverter (VSD). Demand-based operation: The compressor does not operate in an “all-or-nothing” (load/unload) mode. If your system requires only 30% capacity, the compressor reduces its speed and consumes proportionally less energy. Elimination of idle running: Traditional compressors often continue running for several minutes after the tank is filled, consuming approx. 25–30% of nominal power without producing air. Energy Saver models almost completely eliminate this energy loss. 3. Soft Start Thanks to the inverter, these units start smoothly from 0 Hz. This means no sudden current surges during startup, which: Protects the electrical installation in the facility Allows frequent start/stop cycles without the risk of winding overheating 4. Real Energy Savings In practice, the Energy Saver series can reduce electricity costs by 30% to 50% compared to traditional fixed-speed compressors. Additionally, the system maintains very stable pressure in the air network (with accuracy up to 0.1 bar), which is crucial for precision equipment such as laser cutting machines. Extended service life: The absence of sudden pressure and temperature spikes significantly extends the lifespan of the screw element. Technical Specifications Motor power: 7.5 kW / 11 HP Voltage: 400V / 50Hz Air delivery at 0–6 bar: avg. 990 L/min Air delivery at 6 bar: 990 L/min Air delivery at 8 bar: 950 L/min Air delivery at 10 bar: 950 L/min Outlet connection (G): 3/4" Dimensions: 1495 × 600 × 1600 mm Weight: 350 kg

Condition: new, Year of construction: 2026, CORMAK LUFT 700 VSD+PM Compact Screw Compressor with Dryer – Compact Package for Demanding Applications – ENERGY SAVER SET INCLUDES: LUFT 700 VSD+PM COMPACT screw compressor with dryer Horizontal compressed air tank – 270 L Key Features of the Energy Saver Series 1. Permanent Magnet (PM) Motor Technology Most compressors in the Energy Saver series use permanent magnet motors. Compared to standard induction motors, they: Achieve efficiency levels of IE4 or even IE5 Maintain high performance even at very low speeds (standard motors lose efficiency outside their nominal range) Are smaller, lighter, and generate less heat 2. Advanced VSD Inverter Control The heart of the Energy Saver line is the frequency inverter (VSD). Adaptation to demand: The compressor does not operate on an "all-or-nothing" principle (load/unload). If your system requires only 30% capacity, the compressor reduces speed, consuming proportionally less energy. Eliminates idle running: Traditional compressors often run for several minutes after the tank is full, consuming about 25–30% of nominal power without producing air. Energy Saver models nearly eliminate this wasteful process. 3. Soft Start Thanks to the inverter, these units start smoothly from 0 Hz. This means no sudden current surges during startup, which: Saves the electrical installation in the facility Allows frequent start/stop cycles without overheating the windings 4. Real Energy Savings In practice, the Energy Saver series can reduce electricity costs by 30% to 50% compared to traditional fixed-speed compressors. Additionally, the system maintains very stable pressure in the network (with accuracy up to 0.1 bar), which is crucial for precision devices such as laser cutters. Longer service life: No sudden pressure and temperature spikes prolong the screw stage life. Technical Specifications Motor power: 5.5 kW / 7.5 HP Voltage: 400V / 50Hz Air delivery at 0–6 bar: avg. 690 L/min Air delivery at 6 bar: 690 L/min Air delivery at 8 bar: 650 L/min Air delivery at 10 bar: 650 L/min Outlet connection (G): 1/2" Pgedjycg I Sjpfx Amyep Dimensions: 1495 × 520 × 1340 mm Weight: 250 kg