The Hive Window or Door Sensor alerts you if your window or door has been opened or closed when you’re away from home. The clever wireless sensors send an alert to your smartphone if your window or door has been opened or closed. You can turn the notifications off when you know you’ll be at home. Easy to install, use the self-adhesive pad and attach the larger wireless sensor to your window or door and the smaller sensor to the frame. Requires the Hive Hub (if you don’t have Hive Active Heating) which connects all your Hive devices so you can control them with the Hive app.