Introducing the New Yocan Uni Pro variable voltage oil cartridge battery. This latest version of the Uni Pro battery maintains the features of precise adjustable voltage control and user-friendly display screen but has been upgraded to include modern USB-C charging and fits any oil cartridge, including wider 2 gram cartridges. 5 clicks to turn on/off Button activation (hold button to inhale) 10-second preheat feature Manual voltage control buttons (Range: 2.0v-4.2v) OLED screen shows battery life, voltage selection, puff count, & seconds of inhalation Long-lasting 650mAh battery capacity USB-C charge port (charger included) Compatible with all 510 cartridges, including 2g carts (14mm diameter)