Mast Nano Rotary Pen Machine. Pen-style rotary machine for use with needle cartridges. Compatible with all standard power supplies. Machine frame are made from solid rods of high grade aluminum then polished and anodized, laser engraved logo. Machine Specifications: Weight: 82g Size:23mm*78mm Working Voltage: 5-8V Motor: Coreless motor, 8V/9000Rpm Needle Stroke: 3.2mm Battery Specifications: Weight: 64g Size:27mm*78mm Working Voltage: 6-11V Battery Capacity:1200mAh