This is 2 pack of filters that fit: Pleatco: PWW50L | Unicel: 4CH-949 | Filbur: FC-0172 Diameter: 5" Length: 13 1/16" Top: Handle Bottom: 1 1/2" FEMALE SAE Threaded Filter Area: 50 sq ft Filter Material: reemay (3 oz/yard) Alternate Filter Names: 817-0019 | 817-4050 | Rising Dragon 50 | 04-13080 | Twilight TS120 | Twilight TS240 | FW6008 | x268515 | X268514 | X268513 | EP4 | PMAEP4Sk | Used in pools / spas made by: Down East | Four Winds | Ft. Wayne Spas | Hydro Pool Industries | Master Spas | Premium Leisure | rising dragon | Serenity Spas | Waterway Plastics and other manufacturers