Compatible with DSC ER34615M-T1 WT4911 WT4911B WT8911 Wireless Outdoor Siren WT4911BATT, WT4911B, WT8911 models, ALEXOR ADT. Safe and Reliable : Products are CE certified, tested by manufacturer to match OEM standard. built with multiple circuit protection (over-charging, short-circuit, high-temperature, and surge protection), and high-quality. Our batteries are made to the exact specifications and fit exactly like the original. Dependable Security: Designed to meet the demands of security systems, this battery offers dependable power to keep your ADT sensors functioning optimally. Easy do it yourself replacement repair kit.