Pleatco: PFF25P4 Unicel: 4CH-22 Filbur: FC-2399 • Diameter: 4 5/8" • Length: 6 5/8" • Top: Open Hole: 2 3/16" • Bottom: 1 1/2" MPT Threaded • Filter Area: 19 sq ft • Filter Material: reemay (3 oz/yard) Alternate Filter Names: TLX | RLX | FF-150 | 4CH-22 | FC-2399 | SAC0006 | 17-175-1960 | 303263 | PFF 25 | PFF25 W/ PAD-4 AD Used in pools / spas made by: Freeflo Spas | Freeflow Spas and other manufacturers