Wireless RCA Tattoo Machine Battery Great Wireless battery to use with your tattoo machine, or as a back up. Lightweight and long lasting. Comes with USB charger to charge the battery. Specifications: Lithium battery Charging time: 1.5-2 hours charging time for approx 5-6 hours operating. LCD display : Output voltage & Battery power level . Output voltage: 5V-12V - Standard Voltage Display Input voltage: Use the USB cable power for this wireless battery . Weight:70g Size:74.5mm*33.5mm Color:Black-Red Stripe Package Includes: 1 x Wireless RCA Tattoo Power Supply 1 x A USB power cord for charging 1 x Instructions Each machine come with one box Instructions: 1. Power on : Press & hold the middle " O "key for 5 seconds, and then press and hold 5 seconds to power off ; 2. Pause : Quick press the "O" key for to pause, and then press to resume work; 3. Adjust the voltage : Press the + or - key to adjust voltage, corresponding to 1-8 gears representing 5-12V; 4. Battery display : LCD display, 4 cells = Full Charge; 1 cell = Low battery 5. Charging :USB charging - USB Cable included