The FK Irons ONE is engineered for every step of the tattoo artist’s journey. This accessible, wireless tattoo machine opens the door for more artists to create with high-quality equipment at any stage.Premium quality. Sophisticatedly simple.Designed, Engineered & Manufactured in the USA.The FK ONE also arrives with: High-Quality Travel Case with Custom-Cut Protective Foam Two Rechargeable Panasonic 18500A Battery Cells Dual-Battery Charging Dock Product Features: Wireless Operation with Easily Replaceable, Rechargeable Drop-In Battery Battery Type: Panasonic NCR 18500A Battery Note: We always recommend using high-quality batteries, such as Panasonic Quick-Twist Battery Hatch & Power Disconnect LED Voltage Indicator and Colour Spectrum Note: Blinking light indicates 0.5 Volt increment Fixed Machine Body (3.0mm Stroke) New Ergonomic Grip Compatible with all modular FK Grips, including disposable Click grip needle depth adjustment Dual-Battery Charging Dock Charge indicator turns blue once battery is charged Use only included power cable to plug in the dock Compatible with most, standard tattoo needle cartridges How to Operate the Quick-Twist Battery Hatch: Twist clockwise to close & activate the machine’s battery. Twist counter-clockwise to open battery hatch. Push down & keep twisting counter-clockwise to deactivate battery. Note: Cap is shipped in the OFF position