Note : Can not work alone! this magnetic sensor must work with our kerui alarm system.<br />( If you don&#39;t buy the alarm device from our store・we can&#39;t give 100% guarantee that the sensor is compatible with your device.hope your understanding for this.)<br /><br />Use the random equipped double-side tape to stick a magnetic stripe on the door and affix the gate magnetic emission box on the doorframe. Pay attention to put the magnetic strip close to the side with indicator lights of the emission box during installation・ assuring proper alignment and the smaller distance the better.<br />1・ Transmission frequency: 433MHz<br />2・ Operating Power: 23A 12V<br />3・ Built-in Antenna<br />4・ It will send the alarm signal to control host once the door or window is opened <br /><br />Package Included:<br />1 x Wireless KERUI door detector