Usage Tips:Feature: 1. 1400MAH CAPACITY BATTERY: It has a built in 1400mAh large capacity battery, which can continuously work for about 4‑6 hours when fully charged. This feature allows for uninterrupted work on large area tattoos by alternating between two power sources. 2. RING SWITCH CONTROL WIRE: It comes with a ring voltage adjuster. Slide it onto your tattoo pen, and you can easily increase or decrease the voltage right on the ring, making operations more straightforward for tattoo artists. 3. LED DIGITAL DISPLAY: The LED digital display on the the power supply ensures precise voltage output display. Its compact and lightweight design makes it seamlessly integrated with your tattoo pen for smoother operation. 4. WIRELESS DESIGN: Say goodbye to the constraints of traditional power supplies that require numerous accessories to work. It omits power lines, hook lines, and pedal needs, making the tattoo artist work easier and more convenient. 5. ADJUSTABLE VOLTAGE: It is equipped with an adjustable voltage ranging from 5‑12V, with a precise of 0.1V, to meet the speed demands of tattoo artists for different body areas. Specification: Item Type: Wireless Tattoo Power Supply Material: Aluminum alloy, electronic components Size: Approx. 32 x 67mm / 1.3 x 2.6in Battery: Built in Lithium Battery 1400mAh Output Voltage: 5-12V adjustable, adjustment accuracy: short press "+" "-" 0.1V, long press "+" "-" quick adjustment Power Interface: RCA Interface Charging Interface: USB Type C Charging Voltage: DC5V / 1A Charging Time: 3 hours Battery Life: 4-6 hours Power On Function: Press and hold "+, -" keys simultaneously for 3 seconds to enable/disable the power on function. LED Screen Display: Current voltage + remaining battery capacity. Package List: 1 x Wireless Tattoo Power Supply 1 x USB Charging Cable1 x Ring Switch Control Wire