Cartridge finder/Waterway Plastics Top-Load Filter 50Waterway Plastics · spa filterTop-Load Filter 50SeriesTop-Load FilterModel50TypeSpa filterSame replacement partAlso fits these filtersWaterway Plastics 1 1/2-inch In-Line Filter 501 cartridge→Waterway Plastics TWM Cartridge Filter 501 cartridge→Waterway Plastics Dyna-Flo Top-Mount Skim Filter 501 cartridge→Waterway Plastics Ultra Skim Filter 501 cartridge→Waterway Plastics Flo-Pro Skim Filter 501 cartridge→Waterway Plastics TWM Skim Filter 501 cartridge→