Wireless Tattoo Pen Machine with 2.6-4.0mm Strokes Changeable | Mast Flip Pro Mast Flip Pro Wireless brings you more control, convenience and innovation from the inside out to take your skills to the max. Two working methods are available. One is working with the big capacity battery as wireless, another one is with RCA jack as wired. When power depletion, the RCA connector can be replaced. Equipped with LED screen and coreless motor gives you a smooth tattoo feeling. The ¡°Variable On-the-Fly¡± adjustable stroke is what sets the Mast Pro Flip machine from others on the market. Changeable Wireless Or Wired: When power depletion, the RCA connector can be replaced and make work easier. LED Screen: Double-click timing display. Double-click power display. Click voltage display. 1800 MAH BATTERY CAPACITY: 2.5 hours full charging and 5-7 hours operating. The battery weighs only 93 grams.