... work-peices,multi-speed adjustment,the speed of engraving curve lines and straight lines are controlled separetely ... durable, reliable performance, reasonable price, suitable for letters, images engraving on copper, aluminum products, any copper molds, mini die ... Speed0-6000mm/minRotation Speed of Spindle Motor6000-24000rpmEngraving ToolΦ3.175 ,Φ4,Φ6(optional)Dictate FormatHPGLBall ScrewRolling ...