The sophisticated Jane West 510 threaded battery is designed to be used with a wide range of 510 thread cartridges and includes a variable voltage dial, a power button, and our unique moon icon to help you identify your preferred Night cartridge. Simply attach your 510 cartridge, turn on the battery with the power button, and adjust the dial on the base to select your preferred temperature. For added convenience, the battery comes with a geometrically shaped USB charger for when it needs a recharge. Cartridge sold separately.