Tekpower TP152A DC Variable Power Supply, 2.2-15 V @ 2A, Or HY152A
The Tekpower HY152 DC regulated power supply is designed and engineered for tattoo machines. It has a fixed current output at 2 amps, you can control the speed by adjusting the voltage from 2.2 volts to 15 volts, the higher the voltage, the higher the speed.