The Homematic IP window and door contact reliably detects opened or closed windows and doors through an integrated infrared light barrier. The window and door contact is mounted within plastic windows or doors and is conveniently secured with the included adhesive strips. When the window or door is closed, the device is not visible, making it particularly discreet. During ventilation, the room temperature is automatically lowered in conjunction with the Homematic IP radiator thermostat. If desired, an alarm can be triggered in combination with the Homematic IP siren as soon as a window or door is opened. Opened windows and doors are displayed directly in the Homematic IP app, allowing the current status to be checked at any time, even when away from home. The built-in tamper contact notifies users via the app in case of manipulation of the window and door contact.