Steve of Element Tattoo Supply demonstrates how to set up a tattooing power supply, specifically the Silver Bullet model. It has a voltage switch on the back. If in the US, set the power supply to the 115-volt setting. Outside the US, switch to the 220 volt setting. There are two power plugs in front for tattooing equipment (such as a foot pedal), and a dial for adjusting the power. The relative power is displayed on a LED display.