Poolmaster 12791 Replacement Filter Cartridge for Watkins 31114 Filter Equivalent to the following replacement filter cartridges; Pleatco PWK65 and Unicel C-8465 The top of the replacement filter cartridge is open 3 and the bottom is open 3 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