Super-Pro XtremeBlue A7 for Pentair Clean & Clear 520 - Filter Cartridge 4 Pack | X15-ULT-A7-M-Q4 Ladder & Rail Mounting Hardware When the gasket deteriorates

When the gasket deteriorates

While the pump is open for basket replacement

Pentair Max-E-ProXF VS Max-E-ProXF VS Riser plate for XF to Challenger conversion

Lamiclear™ protected against chemicals & UV fading

including angle for depth

Super-Pro XtremeBlue A7 for Pentair Clean & Clear 520 - Filter Cartridge 4 Pack | X15-ULT-A7-M-Q4 Ladder & Rail Mounting Hardware When the gasket deterioratesSuper Pro X15 ULT A7 M XtremeBlue A7 Single Replacement Filter Cartridge, for use with Pentair Clean & Clear Plus 520 Cartridge Filter. This is a FOUR cartridge replacement pack. Clean & Clear Plus 520 requires four to fully service. We recommend replacing all cartridges at once to ensure even and regular servicing of your filter. For the single filter cartridge, see this product.