Features1Adjustable voltage: Voltage range of 4?12V with 0.1V precision, which is allowing tattoo artists to meet the speed requirements of different body areas. 2LED: Large LED digital display screen for precise voltage output monitoring. Compact and lightweight design seamlessly integrates the power supply with your tattoo pen for seamless operation. 3RCA Connector: Universal RCA interface securely connects to most RCA interface tattoo machines, which is ensuring a stable and reliable connection. 4Easy To Use: Say goodbye to the hassle of multiple accessories with this all in one power supply, eliminating the need for power cords, foot pedals, and clip cords, making the tattoo artist's work more convenient. 5Built In 1300mAh Battery: Offers up to 4?6 hours of continuous operation when fully charged, ideal for large scale tattooing with the option of alternating between two power supplies.SpecificationItem Type: Tattoo Power SupplyMaterial: Aluminum alloy, electronic componentsSize: Approx. 31 x 67mm / 1.2 x 2.6inBattery: Lithium battery 1300mAh (built in)Output Voltage: 4-12V adjustable, adjustment accuracy 0.1VPower Supply Interface: RCA interfaceCharging Interface: USB Type CCharging Voltage: DC5V /1ACharging Time: 2 hoursBattery Life: 4-6 hoursStrong Start Function: After power on, press and hold the "+, -" key at the same time for 3 seconds, you can turn on/off the strong start function.LED Screen Display: Current voltage, remaining battery power.Package List1 xTattoo Power Supply 1 x USB Charging Cable