Overview The wireless door window sensor is essential for knowing who is coming and out of your home so it is most 0ften used as part of smart security system SONOFF SNZB 04 is a ZB two in one wireless door window sensor that can be put on your door or window to tell you with an alert notification if your door or window is opened or closed adding an extra layer of security to your home The sensor provides you the possibility to create a scene linkage of ZB and Wi Fi devices Both the opening and closing status of the door window are synced on your mobile phone no longer to think back whether the door down is off or not It is really useful and can help you turn on or off the light in the action Works with SONOFF ZBBridge you can set a scene to get your hallway lighted immediately when the door is opened The camera function can be enabled on the sensor page in the eWeLink APP which also allows you to view clearly who enters your home even you can frighten the stranger and ask him to leave your home immediately with the two way audio function Its application can also extend to wide areas like drawers garage doors blinds etc Just stick it anywhere two things connect and it is always safe even if you don t keep watch on it Share the sensor with your family to give them an ability to quickly control and monitor your home together Simple installation for easier setup Peel and directly stick it on the targeted place or object a smart security system is ready for yo