CS-2029-W,  The CS-2029-w was shipped with an expensive,  'FORM C' relay, a relay

 

that has two contacts in one. The dealer decided which to use and eliminated the

 

other. This was expensive and a waste. The new CS-1829-C/O offers the same benefit

 

in choosing if the contact should be open, or closed, depending on the requirements of the

 

alarm panel by using a simple 3/8 inch single switch contact that is either open or closed.

 

It doesn't matter because the magnet on the unit is moveable to satisfy the zones on the

 

alarm panel.