2400mAh Capacity Battery: Xnet tattoo machine pen has 2400mAh capacity battery, it only need 2-3 hours to full charge, runs for 8-10 hours with one 2400mAh battery, almost a full day's worktime for a tattoo artist. This Xnet tattoo gun battery voltage range is 4-12v, the decibel is 36-39dB when the voltage is under 8V. Besides, there is a RCA adapter coming with the machine which can change from wrieless mode to wired mode.