Features： 1、ULTIMATE VOLTAGE ADJUSTABILITY: 4?12V adjustable and with an impressive 0.1V precision, allowing tattoo artists to meet the speed requirements for different tattooing areas. 2、RCA INTERFACE: Tattoo power supply comes with a standard RCA interface that tightly and securely connects to all standard rotating tattoo machines, ensuring a stable and hassle free operation. 3、CONVENIENCE AT ITS BEST: Tattoo power supply eliminates the need for power cords, foot pedals, and hook lines, making it incredibly convenient for tattoo artists to focus on their work. 4、LONG LASTING BATTERY LIFE: Equipped with a powerful built in 2200mAh battery, which can continuously work for approximately 6 hours on a full charge. 5、LCD DISPLAY: Features a LCD display that shows the current voltage, remaining battery power, working hours, and current frequency. It also has built in shutdown, overcharge, and over discharge protection. Specification： Item Type: Tattoo Power Supply Interface: RCA interface Battery: Lithium battery 2200mAh (built in) Power Size: Approx. 60 x 32mm / 2.4 x 1.3in Input: DC5V 1A Output: 4-12V Output Voltage Adjustment Accuracy: 0.1V, long press can be quickly adjusted Display: Show current voltage, remaining power, working hours, current frequency Charging Time: 1-1.5 hours (strictly prohibited to use chargers higher than 5V charging) Use Time: Can be used for about 7-8 hours Package List： 1 x Tattoo Power Supply 1 x USB Charging Cable 1 x Storage Bag