The pneumatic airbrush is a tool that uses pneumatic power and is commonly used for machining and dressing materials such as metal, wood, and plastics. It works by generating power through compressed air to drive the grinding bit to rotate, so as to realize the processing of the workpiece. With the advantages of high efficiency, high precise and low noise, the pneumatic air-grinding pen is widely used in the fields of machining, automobile repairing and furniture manufacturing. Features: High-speed pneumatic air grinding pen with premium material selection and fine workmanship, using aluminum alloy housing, not easy to rust. The nut and collet chuck are heat-treated, with high hardness, high strength and nice corrosion resistance ability. Stainless steel rotor, 70,000RPM high speed, 30mm long wear-resistant blades, with long durability and long service lifespan. Shipped with two different sizes of collets, 2.38mm and 3mm, you can change collets according to different usage requirements. 1/4 inch threaded air inlet port with high pressure resistant hose for stable and reliable performance. Pneumatic air polishing pen has the advantages of high efficiency, high precise, low noise, etc. It is widely used in machining, auto repairing, furniture manufacturing and other fields. Wide applications, it is suitable for metal polishing, wood carving, mold grinding, burr repairing, etc. Specifications: Name: 7-piece pneumatic air grinding pen set Material: aluminum alloy+stainless steel Rotational speed: 7000ORPM Number of bearings: 3 bearings Working air pressure: 6.3kg/c, 90ib/in2 Collet size: 2.38mm, 3mm Pencil diameter: 20mm Pencil length: 148mm Air inlet thread: 1/4 inch Item size: 243 * 155 * 43mm / 9.57 * 6.10 * 1.69in Item weight: 510g / 1.12lb Package size: 250 * 180 * 80mm / 9.84 * 7.09 * 3.15in Package weight: 515g / 1.14lb Packing List: 1 * Grinding Pen (with 2.38mm collet) 1 * Silencer Tube 1 * 1.2m Air Hose 2 * Wrench 1 * 3mm Collet 1 * Fitting 1 * Empty Oil Pot