24V 40VA Doorbell Transformer - Heavy-Duty Copper Core for Ring Pro/2 & Nest Hello, Easy Install Hardwired Power Supply, Thermostat/Chime Compatible

This Thermostat/Doorbell Transformer is a 24V 40VA power supply that is compatible with Honeywell, Nest, Sensi, and Ecobee Thermostats as well as Nest Hello and all versions of Ring Doorbells. It can work for a 2 wire system (red and white) to connect a new Nest which requires a c-wire. For those who need another 24V source to make it work, they would have to tap into a 120V source, attach it to this transformer at a remote site, and run a wire to where they will be placing the Nest. Most doorbell video cameras state at least 16 volts (though 24 is not excessive) and the same 40VA as this transformer. However, it is advised to contact the company to make sure. In terms of reception, reviewers noted that it was easy to install and was a great purchase for a great price, working perfectly even in sub-zero temperatures. However, one reviewer mentioned that after a year, it buzzes louder and louder, while another mentioned that the transformer was missing one of the screws that connects the wires. Another reviewer mentioned that it should be at a maximum of 24V, within some tolerance but 27 seems a bit high. There are also no installation instructions provided, but people can easily search for an installation video for reference or contact the manufacturer for assistance.