WiFi Sensor for Window, door, and also used as a garage door sensor. Home security door open contact Sensor monitors and reports the opening and closing status of windows and doors in real-time position status displayed on the App, no wiring required. use the app and always know the open and close status of monitored windows and doors in the home. – give you an advanced warning. Extremely easy and fast installations. Using 3M Adhesive installation is firm and durable no tools are required.