Door And Window Sensors Wifi,Smart Door Open/Closed, Battery Not Included Wireless connection?By connecting WIFI and mobile phone connection, whether you are where, Instant notification to your phone immediately when door or window is opened or closed. Multipurpose Sensor:Install the Alarm Sensor not only on front doors or windows, but also on garage doors, liquor cabinets, front gate, safety deposit box, pet doors and more. Easy Installation:Very easy to install via the tapes mount on door or window frame. Tapes and screws included, everything you need to get started is in the box. NOTE: Make sure that the sensor and magnet are aligned and gap less than 10 mm. Compatible with Alexa Google Home:No hub required and No fees charge. Product quality and service:Our products are 100% tested and ensure that all products are qualified products before leaving the factory. Please rest assured to purchase and use.