Does it work have you tried powering it up?
It does says it's pre wired on I assume you just plug the PIR's, Door Contact and Siren in?
You could try some standard PINs, (which I won't state here because it's against the rules) you know the sort of thing you would NEVER use for a card pin number.
Apart from that the only reference to it seems to be this thread.
For £3 it was probably worth the punt.