Two-Way Audio & loop Recording: Two-Way Audio with Noise Canceling-Allows you to talk to your visitors wherever you are. And you can watch real-time videos on cellphone. It also automatically covers the expired video files, easy to manage the monitoring records. 2.4GHz Wi-Fi Connection:Keeping your doorbell always online. IR Night Vision&Smart motion detection:Million HD pixels collocated with wide-angles lens.Which allows you to see clearly in a dark environment at a distance. It could act as a deterrent against to crimes such as theft and vandalism.when someone hovers at the door,immediately alerts push notifications to the mobile phone.