Feature●✅This 24 Volt transformer is UL-certified, offers reliable performance●✅Input :120 VAC, 60 Hz; Output: 24 V/ 40 VA●✅Easy to install: screw down and thread clamps to electrical box●✅Powers thermostats and doorbells: replace underpowered transformers●✅This 24 V transformer fits for Honeywell and Sensi smart thermostats; Nest, Ecobee,Also fit for Ring Video Doorbell, Ring Video Doorbell 2, Ring Video Doorbell Pro, Nest Skybell Doorbell, and other devices that require constant 24 volt power for operationDescription