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