A wired doorbell system has three components: a low-voltage (15- to 20-volt) transformer, a chime and a doorbell button. They are connected by 18- or 20-gauge low-voltage wires. Although it’s at ...

The Nest Doorbell (wired) supports a traditional doorbell chime, but you can now buy one as an add-on to your system to make things a bit more flexible. Launching early next year, Made for Google ...