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 low ...

The Knock does its job, but its motion sensor produced too many spurious alerts and there’s also no way to download captured footage. The Knock is a wired smart doorbell from NuTone, a company better ...