This Wireless Smart Wi-Fi Door/Window Contact Sensor offers round the clock monitoring of your home. Use on doors, windows, cabinets, drawers or anywhere you want to notified when it is opened or closed. Catch every activity and send alert to your Android or Apple phone. It's easy for you to keep an eye on the security of your house anytime, anywhere. It supports 2.4GHz Wi-Fi connection. When it is triggered, such as opened closed or tampered, an instant notification will be reported to your smart phone within 3-10 seconds depends on internet speed. The built-in redial function allow door sensor auto connect to the network after resetting the WiFi router.