Replacement filter for pool and spa cleaning systems * 50% open ABS free flow cores maximize water flow through REEMAY filter media * Antimicrobial end caps resist chlorine degradation and provide support to filter material for a longer life span * Length 23 1/4", Outer Diameter 8 15/16", Top Hole & Bottom Hole 4" * Replaces Unicel C-8412 and Filbur FC-1293 * Made in the USA