Feature: 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 Cable1 x Storage Bag