Sonoff Door Window Sensor RF

**Batteries not included – M27 12V batteries and NOT AA as per the manual**

Doors and windows as the entrances and exits are the weakest points of your home. An unsecured door or window is like an obvious “WELCOME” sign, to a burglar, so door/window sensors are also known as “entry sensor”. As one of the most popular home security devices, DW2-RF wireless door/window sensor is enough smart to get you to know whether your door or window is open, and it can not only send you alert notifications, but also make you know when the entrance point is opened, making sure your home is safe.