Check out Jaycar as they sell all kinds of alarm bits from what
I can remember, won't be a Brant one but it doesn't really need
to be as they all do the same thing and should wire up easily.
If they don't have one the PM "Bumpstop" Macey as he works at
Westside in Cannington and would prob be able to help you out
or at a minimum point you in the right direction.