Unicel FG-2417 Replacement Filter Grid for Anthony Apollo/Flowmaster Diameter: not available; length: 24-inch; width: 17 1/2-inch Top end cap: not available, 0-inch inner diameter; bottom end cap: not available, 0-inch inner diameter Pleat count: not available; filter media: not available; filter area: not available Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications