Specifications: With 2 specifications of 6.0mm and 3.0mm chuck, it is suitable for various grinding heads. Equipped with two disassembly shakers, it is convenient to disassemble and replace the chuck by yourself. The safety protection device prevents misoperation, and the aluminum alloy shell is durable. The air inlet has a filter to prevent impurities from entering the machine. Item Name: Engraving Machine Set Material: Alloy Quantity: 16Pcs/Set Intake Connector: 1/4 inch Working Pressure: 6-8kg Chuck Size: 3mm (1/8 inch )/6mm (1/4 inch) No-load Speed: 20000 R/Min Exhaust Method: Rear Exhaust Features: Durable, Easy to Use, High Hardness Machine Diameter: 3.9cm/1.54" (Approx.) Box Size: 23cm x 19cm x 5cm/9.06" x 7.48" x 1.97" (Approx.) Notes: Due to the light and screen setting difference, the items color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Engraving Machine 2 x Disassembly Wrenches 1 x 3mm Chuck 1 x 6mm Chuck 1 x Air Inlet Connector 5 x 3mm Shank Diameter Grinding Heads 5 x 6mm Shank Diameter Grinding Heads