Two-way intercom: WIFI connection, no need wire, realize two-way intercom between doorbell and mobile phone. Real-time mobile phone, support two-way calls, photos, recording, taking care of your family makes you safer. 100 wide-angle lens: high-definition clear video with viewing angle of 100, display the details in front of your door, reliable and convenient. Large capacity battery and easy installation: charging cycle without disassembly, built-in 800 MAH high capacity lithium-ion battery, charging time 1, 5 o'clock. The doorbell can be controlled by APP, smart and portable. Portable in size and weight, convenient to install and remove Night vision function: equipped infrared night vision, automatic opening at night. Wireless connection, ultra-low power consumption, can support multiple accounts to watch online at the same time. Uses: Guests can make video and voice calls. The host can realize the visitor information without opening the door. Doorbell Features: Master: XR872 Memory: