Feature: 1. 35000rpm high speed grinding, can achieve polishing, engraving, grinding and other technological effects 2. Compressed air is power saving, environmental protection, and simple operation 3. Uses silencer air tube, operate with low noise 4. With a extremely flexible hose with an abrasion guard that allows you to reach the most difficult areas 5. Available in two styles for choices. Specification: Item Type: Pneumatic Grinding Pen Optional Style: A Type-Blue Ordinary Type, B Type-Silver Refined Type Chuck Size: Approx. 3-6mm / 0.1-0.2in Speed: 35000rpm Working Pressure: 6bar Air Inlet Outer Diameter: Approx. 6mm / 0.2in Package List: 1 x Pneumatic Grinding Pen 2 x Wrench 1 x Air Tube 1 x Silencer Tube 1 x Chuck