Unicel 25-sq ft Pool Cartridge Filter

Replacement for: American, Pac-Fab, Hayward, Astral, Waterway ?? - 18" long? - 9-3/4" wide? - 36 sq. ft.??Note: Collar has open slot (2 notches). Length is measured from one end of the grid to the other (collar not included).??Top quality, dependable and durable; these are a few of the reasons why Unicel leads the industry in swimming pool filter replacement cartridges. Unicel filters use a unique, synthetic fiber filter media specially designed for the pool and spa industry, creating exceptional dirt catching ability. Easy to clean and easy to replace make Unicel brand filters a great option for your pool or spa.