2/3/5/10 PCS SONOFF DW2 WiFi Door Window Sensor Wirele Sensor Detector eWeLink App Notification Alerts Smart Home Security Have no idea whether burglars break into your home in your absence? Have you ever imagined that your home lights up at once when you open the door? Or wanna your bed-room light turns off automatically once you walk into the living-room? Any of your ideas will be reality with SONOFF DW2-Wi-Fi wirele door/window sensor. DW2-Wi-Fi comes in two pieces, the transmitter fits onto the door or window and the magnetic switch attaches to the frame. It can help secure your door or window to let you know whether your home is safe wherever you are. The sensor will trigger an alarm to your smartphone to remind you of an intruder when the door or window is opened. Connect SONOFF wirele IP camera and you can view who the intruder is on the sensor page of APP. Whatever your door or window is opened or closed, you can check the real-time opening and closing status on eWeLink APP. Real-time battery level display and low-battery reminder ensure you get clear know how long the sensor can run and when you need to replace batteries. With simple peel and stick installation, it is easy to fit in door frames and window sills.*The sensor can work for up to 3 months if the door/window is opened or closed three times a day.NOTE: DW2 not included batteryNOTE:1. The device only works with 2.4GHz WiFi.2. If the router is working in dual-band (2.4GHz & 5GHz), please upgrade the eWeLink app to V4.0.0 or higher.3. The device shall get close to the smart phone for a good transmiion signal condition while pairing.4.Not support Alexa and Google Home Work Without Gateway Connection No gateway required. The sensor is paired with APP via Bluetooth and is controlled on APP via Wi-Fi Low-battery Reminder There is a reminder on APP if the battery level of the sensor is low Go Back to History Record Automatically save megae notifications. You can check history records over the last 3 month Status Sync, Worry le Worry about leaving your door or window open/closed? View instantly the status of home on APP Can See Who Come into Home Add SONOFF Camera or an unused smartphone, and you can view what's going on in your home not just receive the alert notification when the door is open Always Know Whether Home is Safe The sensor will send you a push notification immediately if someone is detected to open your door or window Install in Second Tool-free installation. Adpots 3M adhesive on the bottom of the sensor for easier installation Features: Keep linkage with SONOFF smart devices to create various smart sceneTurn on/off your light with an actionNotify you when the door/window is openedCheck the opening and closing status of door/window on APPBattery-level display and low-battery reminderAllow sharing the sensor with your family to monitor and control of your homeNo gateway requiredBluetooth low energy pairingSupport to check history record on APPLow-power Wi-Fi transmiion for more lasting work timePeel and stick installation, quick to use