Smart doorbell producer Ring has added $61.2m to the $36m it had already raised from backers including American Family and JF Shea.

Ring, a US-based smart doorbell developer backed by insurance provider American Family Insurance and home builder JF Shea, has raised $61.2m in a series C round featuring Kleiner Perkins Caufield & Byers.

Richard Branson, founder of conglomerate Virgin, also contributed funds to the round.

Ring produces a video doorbell that lets users see and talk to visitors through their smartphone without having to open the door, or when they are not actually home. The technology also includes motion sensors to…