1This spindle comes with forced air cooling and can work for a long time. 2Suitable for engraving PCB, acrylic, drilling, etc. 3Can be used to engrave materials such as metal or non-metal. 43000-12000r/min high speed, low noise operation. 5Chrome-plated surface, smooth texture, rust and corrosion resistant. Condition: 100% Item Type: Engraving Machine Spindle Working Voltage: 12-48VDC Power: 300W Speed: 3000-12000r/min (12V-3000 rpm, 24V-6000 rpm, 36V-9000 rpm, 48V-12000 rpm) Torque: 400mN.m Insulation Resistance: >2 megohms Insulation Dielectric Strength: 400V Diameter: Approx. 52mm / 2in Chuck Part Length: Approx. 35mm / 1.4in shank, (including nuts and core is 43mm / 1.7in) Chuck Part Diameter: Approx. 16mm / 0.6in Total Motor Length: Approx. 175mm / 6.9in (including clamping parts and motor) Spindle Net Weight: 0.8 kg / 1.8 lb(approx.) Spindle Radial Runout: about 0.02-0.05 .w-e-text table td,.w-e-text table th,.wang-edit-text table td, .wang-edit-text table th{border: .5pt solid000;};.w-e-text table,.wang-edit-text table{border: 1px solid000important;}1 x SpindlePlease note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.