1、High Speed Rotation: This pneumatic pencil die grinder set slides across the surface at 58,000 rpm free air speed and 90 psi working air pressure to increase efficiency and provide stable work. 2、Pencil Style Shaft: This air powered micro die grinder kit features a pencil style shaft design that provides control and manoeuvrability when cutting, grinding and polishing surfaces. 3、Multifunctional: This air pencil die grinder kit is versatile and can be applied to cleaning, chamfering, grinding, engraving, and internal processing of various metals. It can also be used for cutting, grinding and lapping plastics, stone, wood, etc. 4、Wide Application: This micro air die grinder set has a wide range of applications and can be used for iron products, woodworking, surface treatment in the tyre industry, shipbuilding industry and so on. 5、Sturdy And Robust: This pneumatic micro air pencil set is made of excellent zinc alloy and nylon material, which is sturdy and abrasion resistant, not easy to be damaged, and has a long service life.