The Hayward replacement filter cartridge is designed for compatible StarClear II filter applications where the internal cartridge element needs replacement. A filter cartridge is useful because it helps capture dirt and debris from circulating water, supporting cleaner water and more dependable filtration performance.This replacement is especially useful when the original cartridge is torn, clogged beyond cleaning, collapsed, or no longer filtering effectively. Replacing the cartridge can help restore better filtration support and improve everyday water clarity.The CX800RE is a practical service part when a compatible Hayward StarClear II filter needs a cartridge to restore dependable filtration performance. Hayward StarClear II replacement filter cartridge Designed for compatible filter applications Helps trap dirt and debris for cleaner water Useful when the original cartridge is worn or clogged Supports cleaner and more dependable filter performance