The buttons on the left are for a simple combination lock. They go like this:
Reset
0
1
2
3
4
5
6
7
8
9
The combination is 2, 4, 6. If you press the NC (normally closed) push button, then that's the equivalent to a door or window being opened, and will activate the alarm (green LED). If you put the right code into the combination lock, then the alarm will turn off (if it is on), and it will be safe to open a door or window for about 10 seconds. The reset button can be used to stop the 10 second timer before 10 seconds have passed.
