NEW 4pcs UltraFire 16340 880mAh 3.7V Li-ion Rechargeable Batteries for Laser Pointer and Flashlight UltraFire 16340 (CR123A) lithium-ion (rechargeable) batteries Length:3.45cm Diameter:1.65cm Capacity:880mAh The voltage of full charge and empty condition is 4.2V and 2.75V Respectively.