Once you go wireless,you will love Ambition tattoo machine. Experience the freedom of going wireless by turning your favorite tattoo machine into a wireless machine. Material: space aluminium alloy Needle Stroke: 4.0mm Motor: Coreless Motor. A advanced gear system tattoo machine pen that offers no give and a 4 mm stroke, the tattoo machine excels in lining, shading and colour packing, and is also very quiet to run and creates minimal vibration. Motor Speed: 12V - 10500RPM Battery Capacity: 1950mAh Charging time: about 2 hours Operation time: about 6 hours Output Voltage : 4.5V-12V LCD display content: output voltage range + battery usage 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. Power: The LED display will show the remaining power and the full power will display 4 divisions. Fast charging through the matching fast-charging cable can usually be fully charged about 2 hours.