Engraving Pen Product Type Engraving Pen Kit Compatible Workpiece Material Ceramic Glass Leather Metal Plastic Wood Duty Industrial Maximum Strokes per Minute 13 500 stroke/min Collet Size 1/8 in Number of Tips Included 3 Tip Types Included 1/4 in Chisel Flat Chisel Round Nose Chisel Required Pressure 90 psi Air Consumption 0.3 cfm Air Inlet Size 1/4 in Air Inlet Type NPT Minimum Hose Size 1/4 in Speed Settings Variable Tool Length 5 in Tool Weight 0.3 lb