With a PIR motion detection camera, two-way audio, and 166 degrees wide-angle lens, get a ring notification anywhere you are! Phone alerts you when visitors are at your front door, you???ll never miss anyone or anything. Talk and see your visitors through your smartphone using the convenient wireless connection. Keep an eye on your door when you are at work or even on vacation. Night vision function offers you a peace of mind at night. OPTA video doorbell, guardian of your home! The OPTA Video Doorbell is equipped with a Passive Infrared Radiation sensor, detecting the slightest motion at the entrance. Get a ring notification anywhere you are! Phone alerts you when visitors are at your front door.When someone presses the doorbell, a notification will appear on your mobile phone. You can answer the door remotely using the app. Communicate directly through your device.Use the app to get the full 166-degree view of your front porch. See your visitors clearly and effortlessly.Switch to night mode on your app, the light sensor on the doorbell will provide a clear view in the dark of night. Video looping automatically overwrites the oldest video files to make room for new footage.The 2.4GHz Wi-Fi range of OPTA Video Doorbell 2 is up to 20m (66ft), it easily connects to your home???s WiFi network, sending live video feed to your phone. You can see and talk to the visitor from the comforts of your bed, from work, or while on vacation.L*W*H=2.93*1.28*5.65inches. Monitor and share to 4 devices. Up to 4 users may view the video feed, but only 1 user can use the direct intercom. iOS and Android compatible.Simple installation, you can mount the doorbell in minutes. The video doorbell can be hardwired to existing doorbell wiring. Rechargeable batteries can also power the OPTA video doorbell. Please pay attention to negative and positive electrode in order to avoid short circuit.