Feature:1. Simple Installation: Wireless intelligent intercom doorbell, ultra long distance transmission, excellent signal through the wall, without wiring.2. 1500m Long Range: With professional interphone chip, the theoretical communication distance in a flat and open place can reach 1500M, making your contact more convenient.3. Multipurpose: Not only used as an intercom doorbell, but also as a daily interphone and an office pager. It can be used in a variety of scenarios.4. Anti Interference: This doorbell doubles as a wireless interphone and will not be affected by WiFi interruption! It will not interfere with other smart devices.5. Wide Application: The waterproof doorbell has a built in low power lithium battery, which can last a long time. It is suitable for home, other fields, companies, teahouses, offices, home stays and other areas.Specification:Item Type: Wireless Intercom Doorbell Material: ABSBattery Type: Lithium Battery (Included).Package List:1 x Door Bell Internal Unit1 x Door Bell External Unit1 x Charger Plug1 x Usb Cable