Extremely discreet and key fob shaped, the LOKEY V2 variable voltage battery is able to vaporize oil cartridges. With 3 different voltages to better suit your needs, this 350mAh battery is compatible with all 510 thread cartridges. Designed with convenience in mind, this battery mod comes with a USB charger built right into the unit for a seamless charging when you need it. Dimensions - 96 x 35 x 16mm 350mAh Rechargeable Battery 3 Variable Voltage Output Levels: 2.7V / 3.1V / 3.6V 510 Connection - Button Activated Loop for attaching to Key chain or Lanyard Integrated USB Charger