This battery Lithium from Tadiran (SL 850) 1/2AA 3,6V 1200mAh is efficient and is made of high-quality material. This batt is friendly for the environment. Tadiran Batteries manufactures high-power Li-ThionylChloride batteries. They provide unrivalled performance thanks to increasingly advanced technologies. The batteries prove capable of operating for over 20 years under challenging conditions.