We recently upgraded our alarm system. This included replacement of the Honeywell Protection Services control panels. We know from experience, that finding replacement parts for Honeywell alarm systems that are no longer being made can be a challenge. We have a D330 Control Panel, a D320 Control Panel, two 4-pin patch cables and a Honeywell 5503 User's Manual.
We have recently seen these panels being sold for $129 each. You can have all of these items for one low price.