Orders of 2 or more will receive a free gift.Smart Security Sensor: door and window alarm sensor is designed to monitor the open or close status of any entrance; An alert notification will automatic send to you in 10 seconds once the sensor triggered; Ideal for front door, window, baby room, garage and more; Door status and battery power can be check in app; No hub required; No extra cost; A must have security system accessories.^ Programmable Sensor: Extend your smart home automation with wifi door sensor; Set up your smart routines in app; Automatically turn on your smart wall switches or lights when door opened; Automatically turn off your air-condition when window opened; More smart devices can be sync as long as they compatible with Smart Life app; Support 2.4Ghz Wifi only, dual-band (2.4G and 5G) WiFf need to set a separate 2.4G channel.^ Hand-Free Voice Control: wifi garage sensor is compatible with Amazon Alexa and Google Assistant; Simply give a voice command to check the open or close status instead of going down or picking up your phone; Your voice device will work as chime, siren or alarm when the sensor triggered; Saving your operation time and make your smart home life more convenient and easier.^ Peace of Mind: All alarm record history can be check in app; The smart window sensor is built-in low consumption module, 2*AAA Alkaline battery provide 1-year monitoring; All the statuses of doors and windows will be displayed simultaneously in the app; Share the device to your families, they can check the status and get notified at the same time.^ Note: The door sensor itself does not include a chime; However, you can program it to some smart voice devices via Smart Life app; When the sensor triggered open or close, the voice devices will perform as an alarm or bell in 10 seconds.