Google also provides a battery-operated video doorbell for individuals who want the facial recognition from the Nest Hello (previously mentioned) but don't have existing doorbell wiring. The doorbell alone operates on CR2032 batteries, which can last for up to a few years, as well as receiver plugs into an outlet. https://dress-belt-womens00877.ziblogs.com/20155991/5-easy-facts-about-round-doorbell-button-described