* If you have many door or window,you can choose N Sensors +N Receivers
* Easy to install, with a hanging hole on the back, which can be hung on the wall or on the desktop; Powered by battery or DC 5V , very convenient and simple to use
* Waterproof transmitter, suitable for indoor/outdoor installation; double-sided sticker or screw can be used
* The Pir motion sensor receiver has low-power detection function. When receiver speaker sound continue from time to time,prompting you to replace the battery. The transmitter uses 3 X AAA batteries and the receiver uses 3 x AA batteries.