This tattoo machine power supply unit features dual inputs, each with a separate control knob, which lets you setup a liner and shader to one power supply. Simply flip the switch and you can easily go from your liner machine to your shader machine and back again. Compact unit with digital display. Measuring 5" in length, 5 1/2" in width, and 3 1/4" in height. DC output from 1.5 to 18 volts and is 1.5 amps. Clipcord and 1 foot switch included.