Pentair 23900-1221S Filter Element Assembly Replacement Sta-Rite System 3 S8D110 SD-Series D.E. Filter Filter element assembly replacement Fits Pentair Sta-Rite System 3 SD-Series D.E. filter model S8D110 Measures 22-1/4-inch length by 14-3/4-inch height by 20-1/2-inch width