【A great fit for home security】: The receiver working together with the window door sensors, making it a burglar alarm system and your 24h private guard. You can put whole-home security at your fingertips with APP whether you are at home or not. Wireless range with 500ft. What's more, you don't need to pay any monthly fees! | 【Powerful DIY】: SmartLife App has built-in defense zone functions and product attributes and has Armed, Disarmed, and Home modes, you can give accessories more personalized settings according to your needs. This door alarm has 10 alarm tones built-in, and you can customize different music for each door sensor(door chime or door alarm). | 【Real-time Notification】: When the door or windows was opened, the receiver will sound an alert and your mobile will receive notifications at the same time as well. Even though you are out of the house you can know when someone break-in your house or your kids, elders slipped out of the house. | 【Expandability】: Add additional components and accessories at any time. Up to 100 wireless detectors or doorbell buttons can be added. In the future, we will provide more accessories for you to choose from, such as window&door sensors, PIR motion detectors, doorbell buttons, etc. | 【Easy installation(2.4GHz Network)】: All accessories in the set are already paired before leaving the factory. This door alarm built in a Bluetooth module. As long as your router supports a 2.4GHz network, you can easily connect to the network by turning on the Bluetooth of your phone and following the instructions.