HQRP Replacement Transformer; POWER UP DOORBELL: replaces and upgrades underpowered transformer with this 16V AC transformer, offering plenty of power for single doorbells; Input: 120V AC; Output: 16V AC 10VA; UNIVERSAL COMPATIBILITY: this 16v transformer compatible with SimpliSafe, Nest Hello, ADT, Zenith, RCA, Ring Doorbell, and other devices that require constant 16 volt power for operation; UL Listed; Safety Features: High Efficiency and Reliability; EASY TO INSTALL; Compatible With 16V 10VA Transformer Compatible with SimpliSafe, Nest Hello, ADT, Zenith, RCA, Ring Doorbell;