Check the listing for details. FK Irons Flux Max Pen Machine 4.5. Color: Black and Gold, Condition: Used. Listed at 600.00 USD. FK Irons Flux Max Pen Machine 4.5 Strokes: 3.2 mm, 4.0 mm, or 4.5 mm Greater Bluetooth Range Full compatibility with FK Irons Wireless Accessories & Batteries Up to 10 Hours Battery Life Weight: 7.23 oz Optimal Voltage: 4V - 12V 9-Watt Brushless Motor USB-C Connectivity The Flux Max senses, adapts, and optimizes to your preferences for a smoother tattoo experience. It features new adaptive technology with a digital display for easy setting adjustment. The enhanced 38 mm ergonomic grip allows for more comfort and precision for the artist. A wide array of settings and built-in timer allows for customization to your unique style. You can now view in both Volts and Hertz for improved accuracy. Available in three different stroke options - 3.2 mm, 4.0 mm, and 4.5 mm. Came with batteries only one is on working order with FkIron app Led display is out. Works very. I’m looking to up grade to 3.5 stroke.