A smart door/window sensor that sends notifications to a corresponding app when the opening or closing of a door or window is detected. Recommended for crime prevention measures while you are out or sleeping. Compact size, can also be used in drawers. Includes adhesive stickers and batteries, ready to use. Unused. - Instant notifications to your smartphone when doors or windows open - Wi-Fi connection supported - Compatible with both iOS and Android - Easy installation, just stick it on, no tools required - Can be installed with a door/window gap of 15mm or less (Example usage scenarios) - Crime prevention for entrances, back doors, and windows - Monitoring while you are away - Checking the entry and exit of children and pets