Package include 1x Air dir grinder1x 1/4" (6mm) collet1x 1/8" (3mm) collet10 x Grinding stones1x 3" (75mm) backing pad2 x Hand Wrenches1x 1/4" NPT connector1x PTFE Tape12x 3" (75mm)Sandpapers (#120/#240/#400/#800 each 3pcs) MOMODA 1/4" Mini Pneumatic Die Grinder Kit This air die grinder suitable for deburring and polishing of variety objects, such as: stone, glass, metal, stainless steel, gems, ceramics, wood, etc., the surface is cleaner and brighter after polishing. The torque output of the pneumatic angle grinder is related to the air pipe.The air angle die grinder is recommended to use a 6.5*10mm air pipe. Product Specifications: Body Material: Aluminum alloy Collet Size: 1/4" and 1/8" Air Inlet:1/4" Air Pressure: 90 PSI Average air consumption: 2.5 CFM Free speed: 20,000 RPM Net wight: 1.0 LB Soft Surface The soft and non-slip shell offers comfortable hand feeling and heat insulation functions, much better than hold a piece of cold metal in the winter. High-power Model This air die grinder is a high-power model. The length of the rotor is 31mm. Not a normal 1" rotor. Up to the maximum unload speed of 20,000 RPM and provides enough power. Rear Exhaust The rear vent design lowers sound level while ensuring vented air does not hit the operator's face. How to install or replace the grinding stone Step1 Use the 11.5mm and 17mm wrenches to loosen the collet cap. Step2 Changing the 1/4" collet or 1/8" collet depending on your needs. Step3 Use the 11.5mm and 17mm wrenches to tighten the collet cap, make sure the collet is installed firmly.