Hayward Star-Clear Plus Knob O-Ring for StarClear Plus Cartridge Filters | CX900H

Description

The Hayward Star-Clear Plus Knob O-Ring (CX900H) is the OEM replacement sealing O-ring for the knob assembly on Hayward StarClear Plus cartridge filters.

IMPORTANT: LUBRICATION REQUIRED — SOLD SEPARATELY
Always lubricate this O-ring with a silicone-based lubricant before installation. Browse our Pool Plumbing Lubricants for a compatible silicone lubricant.

This O-ring seals the knob fitting on the StarClear Plus filter, preventing air intrusion and water leakage at that connection point. Replacing a worn or damaged O-ring at this location restores a proper pressure-tight seal and is a routine part of filter maintenance.

Specifications

Fits Into

Compatibility is based on Hayward parts documentation and available OEM records. This is not an exhaustive list. For certainty, verify the part number in your equipment’s manual or on the original part itself before ordering.

Poolaroo Pro Tip

Before installing CX900H, clean the O-ring groove to remove any residue from the old seal, then apply a thin, even coat of silicone-based lubricant to the O-ring. This prevents the rubber from pinching or rolling during reassembly and extends the life of the seal. Find a compatible lubricant in our Pool Plumbing Lubricants collection.