The Pentair 59052900 Locking Ring Assembly fits the Pentair Clean & Clear cartridge filter, the Pentair Predator cartridge filter and the Pentair Warrior DE filter. The Locking Ring has buttress style threads on the inside and has 2 spring loaded locking tabs. The outside diameter of this ring is approximately 13-1/4 inches, the inside diameter is approximately 12 inches and the height is approximately 2-1/4 inches.