Each Zmodo Greet package includes a Zmodo Beam, a smart hub that connects your Zmodo accessories including door and window sensors and boosts your Wi Fi range. What can you expect?You'll receive a push notification when someone presses the doorbell or activates the motion sensor. You'll also get on demand access to live 720p HD video. This device is also weatherproof and comes with built in night vision. Best of all, when you aren't around to answer the door, it can be set to play a personalized voice message. Do note that when you're installing it, you’ll need to wire it to a power source.