Poolmaster 12923 Replacement Filter Cartridge for Leisure Bay S2/G2 817-0016 and 303434 Filter The corresponding Pleatco number is PLBS100 and the corresponding Unicel number is C-5397 The top of the replacement filter cartridge is open 2-1/8 and the bottom is open 2-1/8 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