Waterway Crystal Water Cartridge Manifold Plug (519-4320) gridcontrols and FC-9850 reference give this

and FC-9850 reference give this part practical value because DE filter components work best when the replacement matches the original size and internal design closely

This Balboa M7 15 inch 5

A properly selected cartridge helps restore intended filtration performance and contributes to cleaner maintenance routines

Almond bezel and actuator component from Jacuzzi Whirlpool Bath

Waterway Crystal Water Cartridge Manifold Plug (519-4320) gridcontrols and FC-9850 reference give thisThe Waterway 519 4320 cartridge manifold plug is designed for compatible Crystal Water cartridge filter systems. A manifold plug like this is an important service part because it helps complete and seal the manifold area properly, supporting correct assembly and dependable filter operation. Small internal components can have an outsized effect on maintenance quality, especially in filtration systems where a missing or damaged plug can interfere with