Compatibility - Works with the following Dolphin robot pool cleaners: Active 20, Active 30, Active 30i, Active 40, Active 60, Advantage Ultra, Discovery (New), Explorer E30, Explorer E50, Explorer E70, M600, Mercury, Premium, Proteus DX4, Proteus DX5i, Prowler 920, Prowler 930, Prowler 930W, Quantum, S200, S300, S300i, S400, T35, T45, T55i, Triton PS, Triton PS Plus, Warrior SE, Warrior SL. Part Number: 991467-R4 Construction and durability - Built with a heavy duty ABS plastic frame and an ultra-fine pleated filter paper, it firmly supports the filter layer to prevent operation interruption. The pool water flow remains stable, ensuring maximum hydraulic efficiency and overall structural stability during operation. Cleaning and maintenance - The 9991467-R4 multi-layer ultra-fine filter is easy to clean: rinse with a hose, reinstall, and you’re done in minutes. After washing, the filter looks almost brand new. Filtration performance - Thick pleated fabric captures sand, leaves, hair, and debris more effectively than ordinary fabrics, delivering improved filtration efficiency for clearer pool water. Use scenarios - Regular pool maintenance with Dolphin robot cleaners during the season to maintain crystal-clear water. - After heavy rainfall or storms when debris increases, to quickly restore water quality. - Before hosting a pool party or opening the pool for the season, to ensure optimal filtration and clarity.