Nest Hello Smart Wi-Fi Video Doorbell - White/Black (NC5100US)The Nest Hello Smart Wi Fi Video Doorbell, White and Black version. Model: (NC5100US). Nest Hello lets you know whos there, so you never miss a thing. It replaces your existing wired doorbell and delivers HD video and bright, crisp images, even at night. Its designed to show you everything at your doorstep people head to toe or packages on the ground. And with 24 7 streaming, you can check in anytime. Or go back and look at a 3 hour snapshot history