4 5 / 8IN. x 13 1 / 2IN., 2IN. Internal SAE thd, Rising

Replacement filter 50 square feet equivalents on the market are Filbur (FC-0172) Unicel (4CH-949) & Pleatco (PWW50L). Diameter 4 15/16'' Height 13 1/2''. Top closed with handle and bottom 2'' SAE. Manufacturers using this filter: Dragon Rising, Hydropool Spas, Sunrise Spas and Waterway plastics.