Power units from MT Derm/Cheyenne are compatible with tattoo machines from Cheyenne, but also work perfectly in combination with other tattoo machines. The Power Unit lll is a hygienic and technical masterpiece - once in operation, the unit works completely contact-free. Contains 2 USB outputs for charging additional devices. Thanks to its magnetic back and bottom, the Power Unit lV guarantees a secure hold, has intuitive operation and a voltage range of 4.7 to 12.5 volts.