Magnetic door contact 
This is an advanced  magnetic  contact sensor with integrated RF transceiver designed to be a fully supervised low-current device.
A built-in reed switch and/or an external wired input may be applied in this device.
To maximize security, an 8.2k end-of-line resistor is monitored on the external wired input.
Features
Internal Reed Switch
External Terminal Block for wired connection
AND/OR Mode available
Coverage 150m in open space
Powered by 1 lithium battery CR123
Battery life more than 4 years
Configurable over-the-air by the Base Station
Tamper Switch: Front cover and back tamper
Multicolor LED indications