1、WORK PARAMETERS: Air die grinder pen kit, with no load speed of 55000rpm and a working pressure of 90psi, has high efficiency and low consumption. 2、METAL GEAR SET: The pneumatic grinding pen adopts tungsten steel alloy gear set, which is wear resistant, improves grinding speed and efficiency. 3、PORTABLE DESIGN: The air die grinder is pen shape design that can be used with one hand, suitable for engraving, grinding, polishing in narrow areas. 4、APPLICABLE MATERIAL: The pneumatic grinding pen can be used for metal, plastic, stone or wood processing, can be used for grinding, polishing and cleaning. 5、STANDARD INTERFACE: This air die grinder pen has 1/4in standard inlet port, stable connection without leakage, equipped with hose and filter, convenient to use.