SONOFF DW2 Wifi Wireless Door Window Sensor Open/Closed Detectors e-WeLink APP Features: Keep linkage with SONOFF smart devices to create various smart scene Turn on/off your light with an action Notify you when the door/window is opened Check the opening and closing status of door/window on APP Battery-level display and low-battery reminder Allow sharing the sensor with your family to monitor and control of your home No gateway required Bluetooth low energy pairing Support to check history record on APP Low-power Wi-Fi transmission for more lasting work time Peel and stick installation, quick to use Note: SONOFF DW2 doesn’t come with batteries into package. Specification: Battery Model: AAA 1.5V; Working Voltage: DC3V (2 x 1.5V battery-Not included); Quiescent current: ≤ 40 μA; Wi-Fi: IEEE 802.11 b 2.4GHZ; Material: PC V0; Package list: 1 x SONOFF DW2 Wifi Wireless Door Window Sensor Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Dadangjia