Pentair Compool CP30/CP100 Freeze Sensor (FPSAUX) senasys A seal plate is useful

A seal plate is useful because it helps support the mechanical seal area and acts as a key structural link between major wet-end components

more visually present trim face at the spa surface

Match the listed MFD

Balboa 15" FloThru Heater Assembly [4kw] [2X2] (58111) is engineered with a clear focus on flow-through efficiency

Pentair Compool CP30/CP100 Freeze Sensor (FPSAUX) senasys A seal plate is usefulDesigned for lower horsepower Challenger High Flow pumps, this diffuser supports steady water direction around the impeller. It can help restore proper wet end operation when the original diffuser has been damaged by wear, debris, or heat. Because diffuser fit affects priming and flow stability, it is an important part of a complete pump refresh. Choose this replacement when you want a clean, part specific repair rather than forcing a workaround that