【PHTA MEMBER – TRUSTED QUALITY】 As a proud member of the Pool & Hot Tub Alliance, TOREAD aligns with industry-recognized standards for filtration performance and safety, delivering reliable quality and consistently cleaner water you can trust. 【NSF/ANSI 50 CERTIFIED】 TOREAD Pool and Spa filter is tested and certified by IAPMO against NSF/ANSI 50. The filter with certified safe materials provides you with clean, fresh and clear water. Only select certified filters for your family to ensure the safety, health and happiness of your loved ones. 【SPECIFICATIONS】 Length: 9 1/4”; Outside Diameter: 5”; Top /Bottom Opening: 2 1/8”; Filtration Area: 35 Sq.ft; Filter Material: Trilobal Filtration Fabric. 【REPLACEMENT MODELS】TOREAD TRF-4335 filter compatible PRB35-IN, Unicel C-4335, Guardian 409-219, Aladdin 13501, SD-00198, SD-00659, Rainbow Dynamic 35, Waterway 35 In-line. NOTE: This is a compatible spare part and the manufacturers' names and part numbers have been used for reference purposes only. TOREAD is an independent brand. 【REINFORCEMENT STRUCTURE】Our filter features a comprehensive reinforcement design, including heavy chlorine-resistant and break-resistant end caps, and a reinforced center support.With 25% thicker filtration fabric for superior dirt-holding capacity.This robust construction delivers high-powered propulsion flow and crystal-clear water, ensuring a relaxed and healthy spa experience. 【MORE EFFICIENT FILTRATION AREA】Achieve crystal-clear water with less maintenance. Our filter's secret is its high-performance trilobal fabric, which provides 21-40% more capacity and superior particle capture than standard filters—all without sacrificing water flow pressure for a truly efficient and relaxing spa experience. ⚠️ Not for Backwashing – This filter cartridge is not designed for backwashing. Backwashing may cause cracks or permanent damage. Also compatible these filters: Aber Hot tub, After Hours Spas (Hydro), Belize Spas, Bullfrog Spas, Coast Mountain Spas (Canada), Coleman Spas, Columbia Spas, Crystal Waters Spas (Canada), Custom Molded Products, GPM Industries, Gulf Coast Spas, Great Lakes Spas, Hydro Pool, Hydro Pool/Serenity Spas, Hydro Spa, Hydro/After Hours Spas, Leisure Bay/Rec Whs, Moose Mountain Spas, Orca Bay Spas, Rainbow/Pentair, Rec Whs/Leisure Bay, Vita Spas, Serenity Spas (Hydro Pool), Sun Ray Spas, Waterway Plastics, Wind River Spas Aladdin 13501, Baleen AK-3015, Darlly 40353, Excel Filters XLS-418, Filbur FC-2385, Filbur FC-2385M, Harmsco H-4335, Magnum RD35, PRB35-IN, PRB35-IN-M, Pure N Clean PC-2385, SD-00198, SD-00659, Unicel C-4335, Unicel C-4335RA, 303557, R173431, 03FIL1300, 13501, 13501ECO, 17-175-1608, 17-2482, 25393, 3501, 4900-35, 609503, 645544023858, 645544123855, 817-3501, 9348-192, 303654, 425636, 425974, 609503, 673030, APCC7110, APCC7501, FC-2385-HB, P-4335, PC-2385, PLE-051-9177, PLE-051-9178, PRB35-IN ZEO, PRB35-IN-ZEO, SC705, UNIC4335, Rainbow / Pentair Dynamic 35, Waterway 35 In-line