wireless door contact;

function and specification:

the device consisted of  two parts, the wireless emitter part and the magnetic bar,
the wireless emitter part is mounted into the fixed door edge, and the magnaetic
bar is mounted on the edge of the moving door edge, the two parts must be closed
when the door is closed, when the door open,the two parts will also move apart
, so the magnetic bar will lost its effect on the emitter part, which make the
emitter to emit a wireless signal out to another alarm control unit.  

wireless frequency: 315MHz/433MHz.
wireless distance: 100m open area
installation please assure the the two parts be closely fixed, the gap not more than
1.0cm.  the two parts should not closely mounted on the surface of metal materials,otherwise
the distance will be shorter.