Composed of 3 of the specialized Nickel Metal Hydride 2/3 AA batteries, this battery pack is designed to replace a wide variety of battery packs from an assortment of brands including Uniden, V Tech, Radio Shack, and many more. Its NiMH chemistry allows the pack to hold a substantial charge, up to 750 mAh and can produce up to 3.6 Volts of power.