Poolmaster 12712 Replacement Filter Cartridge for Preditor 50 R173213 and 59054000 Filter The corresponding Pleatco number is PAP50-4 and the corresponding Unicel number is C-9405 The top of the replacement filter cartridge is open 6 and the bottom is open 6 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