These 18650 batteries provide high performance and can be recharged up to 500 times, saving you money in the long run. Each battery comes equipped with a built-in circuit protecting board and triple over-heat protection. Olight has thrown in a higher capacity and lowered the weight opposed to other 18650 batteries. You don't have to worry about over-discharging the battery as you are protected there as well. --Features: -500 recharge cycles -Triple over-heat protection -Over-discharge protection -High capacity at low temperature (-10°C) -Higher capacity and lower weight than other rechargeable batteries -Higher energy density -Free from leakage of Liquid Electrolyte --Specifications: -Battery Size: 18650 -Chemistry: Li-ion -Voltage: 3.6V -Capacity: 3400mAh -Charge current: 1700mA (0.5C) -Maximum charge current: 3600mA (1C) -Maximum discharge current: 4200mA -Diameter: 0.7" (18.6mm) -Height: 2.7" (69.5mm) -Weight: 1.7 oz (49g) PRC