Anker eufy Entry Sensor E20

The eufy Entry Sensor E20 secures your doors and windows. You connect your device to the app when you receive it. To use this sensor, you always need a eufy HomeBase (HB Pro, HB3, or HB2). As soon as someone opens a door or window, you'll get a notification right away via the eufy app. This way, you'll always know what's going on, even when you're not home. The sensor is also small, so it fits on almost any frame without standing out. The battery lasts up to 5 years, so you won't have to worry about an empty battery. With this sensor, you can be sure your windows and doors are closed. That gives you a safe feeling, and it helps prevent children or housemates from accidentally leaving a door open.