Review on Universal 24V 40VA Thermostat / Doorbell Transformer: Compatible with Honeywell, Nest, Sensi, Ecobee, Nest Hello, and Ring Doorbells by Stephen Doyle

This transformer is way too hot for Ring Doorbell Pro. The output of this transformer at the doorbell was 26.5v and it fried it. I returned the Ring Doorbell Pro to Costco and bought their Doorbell 2 (in warehouse) bc I didn't feel like extending my weekend doorbell replacement project for another week. Before installing new doorbell, I bought a 3 output regular bell transformer from big warehouse hardware store. Used the 16v output and measured 18.5v at the bell. It powered it flawlessly and my project is done.