Mast Rotary Tattoo Machine Pen for PMU SMP. This Machine have Innovative driving principle, more quiet sound and more stable operation. Internal spiral needle length mechanism, more precise design, then adjusting the length of the needle, the position of the needle will not change. Powerful magnetic attraction,compatible all standard cartridges can be used for eyebrows, lips, scalp and small tattoos. Specifications: Weight: 77g Diamater: 18mm Length: 112mm Stroke: 3.6mm Speed: 12800 RPM Suggest lining voltage: 9V Suggest shading voltage: 8V