Ambition Rotary 2400mAh Battery Pen Tattoo Cartridge Machine with Japan Coreless Motor Wireless Power Digital LED Display Tattoo Equipment Supply for Professionals and Beginners Tattoo Artists Material: space aluminium alloy Needle Stroke: 4.0mm Motor: Japan Coreless Brushless Motor Motor Speed: 10V - 9000RPM Battery Capacity: 2400mAh, biult-in 3x 800mAh lithium battery Charging time: 1.5-2 hours Operation time:Under normal 8V voltage, the voltage stable state can last for more than 5 hours,long time working the voltage is stable. Output fixed current：1A Working voltage: 3.7V Output Voltage : 5V-12V LED display content: output voltage range + battery usage + working time Instructions for use: - Power ON/OFF: Long press "O" key for 3 seconds - Output pause / resume: Short press "O" key to pause the output, and short press it again to resume the output(the resume voltage is the working voltage before the pause). - Adjust output voltage: Press the "+" or"-" key to adjust output voltage. The voltage can be adjusted through button (+) and (-) respectively with the voltage of 0.5V on each press. - Working time: The working time can be accurate to minutes. When the power is turned off, the time will be cleared. When the output is paused, it will also stop counting. Power: The LED display will show the remaining power, and the full power will display 4 divisions. Fast charging through the matching fast-charging USB data cable can usually be fully charged in 2-3 hours. Please pay attention to the change of power at any time to prevent sudden power loss from affecting your tattooing work.