Dimension One Crystal Pure Ozone Replacement Filter Cartridge. Has a open top and bottom with the top having a a slightly smaller hole and a ring around the top of it. The top ring contains 12 holes around it and the filter is core less. Filter dimensions: Height- 302mm(end to end not includins top ring), Width- 140mm, Hole ID Top- 50mm, Hole ID Bottom – 72mm. Commonly used on the Crystal Pure System
