e doorbell

1. Built-in bluetooth 4. 0. 2. Work with Android+IOS APP application. 3. Alarm host and doorbell functions dual work. For example, when front door sensor under arm status, it can trigger host. Alarm when somebody break into your home. But when the front door sensor. Under disarm status, the host will make "ding-dong" doorbell sounds to remind. User somebody is coming.