FEEMO MAGIC 510 battery. This device features a 510 threaded base that magnetically inserts into the case to both hide and protect your hemp or THC cartridge. The Box uses a 650 mAh rechargeable battery that offers 3 voltage settings, a pre-heat function, and a draw or button activation firing mechanism. Auto-draw or button-firing mechanism Pre-heat function Supports up to 2g 510 threaded cartridges (Applicable Max size:15mm(D)*63mm(H)) Magnetic bottom connection Variable Voltage: 2.8V-3.2V-3.6V-4.0V Battery Capacity: 650mah Auto shut-down: In stationary state, the white light flashes 3 times after 1h of non-use and then turns off Type-c Charging Port Over charging,Low Voltage and Short Circuit Protections It is better to preheat before use