Poolmaster 13217 Replacement Filter Cartridge for Star-Clear Plus C-1750 CX1750RE Filter Equivalent to the following replacement filter cartridges; Pleatco PA175 and Unicel C-8417 The top of the replacement filter cartridge is open 4 molded gasket and the bottom is open 4 molded gasket Break-resistant bands keep pleats separated for greater flow, filtration and add longer life to cartridge High quality spun bonded polyester material for exceptional water filtration Premium grade polyurethane and plastisol end caps