Replacement battery for your favorite Strion flashlight. This battery is made by Streamlight, and it's a brand that's relied on by many law enforcement and military personnel, as well as civilians. This is a lithium-ion (li-ion) battery in terms of chemistry, and it is rechargeable. Its voltage is 3.75V, which is more than twice the voltage of an alkaline primary battery, for comparison's sake. It has a capacity of 2Ah (2000mAh), which will feed a great deal of power and energy into your Streamlight Strion flashlight. It is capable of up to 300 charge-recharge cycles, so you'll be able to get your money's worth out of this battery. This battery is a protected cell because it contains a control circuit that is part of the internal structure of the battery; it is built in for the user's safety.