Includes a 510 thread rechargeable lithium ion battery and USB charger – calibrated specifically for B40 Vape Cartridges The Back Forty Vape Battery & Charger includes a 510 thread rechargeable lithium ion battery and USB charger. The Back Forty Vape Battery is calibrated specifically for B40 Vape Cartridges. Back Forty Vape Cartridges are sold separately.