Pleatco PD40SL-4 Replacement Cartridge for Doughboy 40, 1 Cartridge 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 9-1/8-by-1-1/2-inches with handle Made in the USA