2 Guardian Pool Spa Filter Replaces Unicel 4CH-24 Pool Filter 25 Sq Ft Filbur FC-0131 Pleatco PGS25P4 2 Pack Replaces Unicel 4ch-24 Diameter: 4 5/8" Length: 9 3/4" Top: Handle Bottom: 1 1/2" MPT Threaded Filter Area: 25 sq ft Filter Material: reemay 3oz Replaces Pleatco: PGS25P4