Thermostats with C Wire Adapter, 24 Volt Transformer 

Ecobee, Nest, and Honeywell Smart Wifi Thermostat compatible, (White) Ring Nest Hello Skybell August Doorbell

Plugs into a standard 110/120 volt outlet and converts the voltage to 24 volts AC

A 24 volt transformer for smart thermostats (Nest, Ecobee, Honeywell, Emerson Sensi, Hive, etc.) and doorbells (Ring, Nest Hello, Skybell, and August).

24V transformer with UL certification, stable and durable operation

A 23-foot cable allows you to plug it into an electrical outlet inside or outside your home, and its non-polarity wires facilitate easy and quick installation.

One C wire adapter with a 25-foot cable is included in the package