Features : 1 . The head of the pen adopts special alloy steel , quick, flexible and comfortable to use . 2 . Depending on the difference of the material , depth may be up to 1 mm . 3 . The main body is made of synthetic material , lightweight and convenient to use . 4 . Compressed air , energy saving and eco friendly . Noise reduce intake pipe , comfortable to use . 5 . Works great on metals , wood , plastic , glass , stone , china and other hard material , great for marking tools , components , and more . Specification : Item Type : Pneumatic Engraving Pen Material : Aluminum alloy , Iron , Steel Model : KP 612 No load Speed : 3800 times / min Working Pressure : 0 . 6 mpa Inlet interface : 1/4" Noise Reduction Tube : 1 . 5m Package Weight : Approx . 309 g Package Include : 1 * Pneumatic Engraving Pen