Balboa Circuit Board - X-P632 53680 Extender [2 Relays] (53680) presairtrol and this Filbur FC-3753 cartridge

and this Filbur FC-3753 cartridge is designed for C-4313 and PBW4PAIR applications

4 inch relationship give this part practical value because structural filter components work best when they match the original assembly size and geometry closely

The Waterway 3421020-1U Executive pump is designed for compatible applications and features a 3

Useful when original bearings are worn or noisy

Balboa Circuit Board - X-P632 53680 Extender [2 Relays] (53680) presairtrol and this Filbur FC-3753 cartridgeExtension and relay boards are the kind of parts that make a spa control system more capable without replacing the entire platform around it. This X P632 extender board with two relays is designed to support compatible systems that need that added control capacity or functional extension in a cleaner, purpose built way. When an extender board fails, the symptoms can be frustrating because they often seem scattered. Certain accessories may stop