The doorbell you've been waiting for! Nest Hello lets you know who's there, so you'll never miss a thing. It delivers HD video and bright, crisp images, even at night. It's designed to show you everything on your doorstep – people head to toe or parcels on the ground. Requirements Nest Doorbell installation requires a wired doorbell, chime and compatible transformer. The chime and transformer will need to be purchased separately. See below the compatible chimes and transformers for … [Read more...] about Nest Hello Doorbell – Which chime and transformer?