This is a 16VAC, 30VA doorbell transformer. Connect the input of this transformer to 120VAC to the corresponding wires, and the output is screwed to the 16VAC low-voltage terminals for a more secure connection. You can easily power single or multiple doorbells in a home. Replace your old, underpowered doorbell transformer for better performance. It is compatible with many doorbell transformers, including Ring Video Doorbell Pro, Nest Hello Video Doorbell, and more.
