DX 433Mhz Wireless Door Contact 248919
From SifWiki
This is based on a EV1527 encoder and therefore works with RCSwitch. They're detected as 24-bit protocol 1.
The two devices I have report their id's as;
Alarm Sensor: 13857492 110100110111001011010100 Alarm Sensor: 9373908 100011110000100011010100
Device is a pretty simple reed switch with a magnet, normally closed and triggered when the connection is broken, this should be easy to hack to other usage.
Affiliate link to DealExtreme: http://dx.com/p/248919?Utm_rid=65939668&Utm_source=affiliate