Unicel C-5404 Replacement Filter Cartridge for 40 Square Foot Ozone Cartridge， Dimension One Spas<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Diameter: 5 1/2-inch; length: 17-inch</li><li>Top end cap: open with 12 concentric holes， 1 15/16-inch inner diameter; bottom end cap: open， 2 7/8-inch inner diameter</li><li>Pleat count: 133; filter media: 4-ounce reemay 2040; filter area: 40 square feet</li><li>Get more efficient filtration and better water clarity with Unicel filters</li><li>Longer time between cleanings; meets oem specifications</li></ul></div><img src="http://ecx.images-amazon.com/images/I/31xMub%2Bw6RL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/31f-8luVzyL.jpg" noproxy>