Whether you are home or away, this entry sensor will send push notifications to alert you when the door/window this is fitted to is opened or closed. 24/7 monitoring: Detect door/window opening and closing in real time - receive instant alerts when door/window is opened or closed Easy Installation: Simple do-it-yourself installation, no gateway product required connects via Wi-Fi and SmartKnight app. Low power consumption: Uses ultra-low-power MCU and Wi-Fi module with a range of up to 40m (dependent on environment) Automate: Set devices to automatically turn on or off as door/window is opened or closed, such as a light Wi-Fi Connectivity IEEE 802 11 b/g/n (2.4Ghz only) if you have a Dual Band system simply disable the 5Ghz frequency in your Wi-Fi Router* during set up and then enable again once set up is complete Low battery alert - never forget to change the battery Battery type: 1 x DC 3V CR2 battery (included) Battery Life: 1 year (if activated 20 times a day) *