The Mast Tour Pro rotary tattoo pen machine is a durable machine with pen-like design, Flexible and light weight for every style Gently and smoothly transfers ink to skin; suitable for all skin types. Effortless to cover and protect Efficient cartridge change and replacement. Compatible with power supplies and wireless power batteries with start-up function, direct drive working principle suit for all kinds of tattoos. Specifications: Net Weight: 127g Machine Diameter: 32mm Machine Length: 85mm Needle Protrusion: 0 up to 4mm Stroke Length: 3.6mm Suggest Voltage: 5-8V Motor Speed: 7.5V/1000Rpm Continuous, quiet, and gentle operation Custom Mast coreless motor