Alarm sensor

So I got this alarm sensor over my door. Been there since I moved in. The system never worked. This thing had a magnet attached to the door. Any ideas for arduino? Can I use arduino with this? It has terminal blocks.

It is a wireless transmitter. I see two reed switches, a RF transmitter module, antenna, space for battery, a button and a chip. The terminal block is for an extra alarm I think.

What does the receiver (the base station of the alarm) look like ?

Most of those use 433MHz with ASK modulation (on/off) and a protocol that can be read and transmitted with the RCSwitch library. On Ebay there are many ASK modules.

The RF transmittor module in the picture is a RFM N5970. That is 345.0 MHz. A weird frequency, I think it is not legal to use it.

Conclusion: Old, unknown and perhaps not legal to use. Sorry, but you better toss it away.