Feature: 1. SCIENTIFIC DESIGN: Tattoo pen using ergonomic design to provide you with a comfortable grip, and the surface of the tattoo pen with a non slip design, you will not get tired when use it for a long time, which is more secure. 2. ALL IN ONE: This tattoo pen does not need an external tattoo power supply, tattoo foot pedal and clip cord, which abandoning the traditional way of tattooing, more convenient and fast. 3. NORMAL MODE: This tattoo pen can also use the RCA connector to connect RCA clip cord to convert to normal mode, which liner and shader can be compatible. 4. EFFICIENT: Bulit in high performance motor, 4.2‑12V adjustable voltage, and has strong power. When the voltage is 12V, the speed can up to 12000RPM. The tattoo pen is durable and stable during the operation, which is low noise and easy to color. 5. 1900MAH: Tattoo pen built in 1900mAh high capacity battery, 2 batteries can be used alternately, which can be used for 8-12 hours, strong endurance. 6. OLED DISPLAY: Tattoo pen using OLED display, which can clearly display the current tattoo voltage, remaining power and convenient for tattoo artists to observe the state of the tattoo pen at any time. Specification: Item Type: Tattoo Pen Kits Material: Aluminum alloy, electronic components Matching Battery: 2 x 1900mAh lithium batteries 18500 Tattoo Pen Size: Approx. 140 x 32mm / 5.5 x 1.3in Storage Box Size: Approx. 26 x 13.5 x 7cm / 10.2 x 5.3 x 2.8in Adjustable Voltage: 4.2-12V Adjustment Accuracy: 0.3V Needle Stroke: Approx. 3.5mm / 0.14in Speed: 12V 12000RPM Needle: Universal tattoo cartridge needle on the market Display Screen: Voltage, remaining power Charging Time: About 2.5 hours Working Time: 2 batteries fully charged alternating use, can be used 8-12 hours Voltage Light Changes: 4.2-4.5V Blue 4.8-5.1V Cyan 5.4-5.7V Rose Red 6.0-6.9V Dark Green 7.2-7.5V Light Green 7.8-8.4V Yellow 8.4-8.7V Dark Green 9.0-12V Red. Package List: 1 x Storage Box1 x Storage Box Key1 x Tattoo Pen1 x RCA Conversion Head1 x RCA Clip Cord 1 x Battery Charging Case2 x Battery1 x USB Charging Cable