GALLOPJOY Novelty Shining Attractive 4X Trustfire 10440 Li-Ion Lithium Battery Model: TrustFire TR 10440 Capacity: 600mAh Voltage: 3.7V Li-ion Lithium Battery Warning: The voltage of full charge and cut-off discharge is 4.2V and 2.75V. Dont heat, incinerate or reverse polarity.