HQRP® Replacement Transformer; UL Listed;. Input: 120V AC; Output: 24V AC; 40VA;. Compatible with 4011OF 503625 HVAC Furnace Multi Tap Power Supply Adapter 120v-to-24v;. UNIVERSAL COMPATIBILITY: this 24v transformer fits for Nest, Ecobee, Honeywell and Sensi smart thermostats; Also compatible with Ring Video Doorbell, Ring Video Doorbell 2, Ring Video Doorbell Pro, Nest Skybell Doorbell, and other devices that require constant 24 volt power for operation;.
