Professional Copper Made Tattoo MachineSpecifications: Pure copper contacts deliver great electrical conductivity and tapping strength. Neatly and tightly twined coils, soft and stable frequency. Highly flexible spring sheet provides large, precision work space, fast coloring. Capable of long time continuous working without giving off too much heat. Baking varnish finish, fine workmanship. Start at 4V and work well at 7 8V Material: Copper Coils: 10