Unicel C-9407 Replacement Filter Cartridge for 75 Square Foot Predator, Clean and Clear, Cal Spas Diameter: 10 1/16-inch; length: 16 1/8-inch Top end cap: open, 6 0/0-inch inner diameter; bottom end cap: open, 6 0/0-inch inner diameter Pleat count: 171; filter media: 4-ounce reemay 2040; filter area: 75 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications