Ultimate Dual KDF Shower Filter Replacement Cartridges

This product may take 1-4 weeks from order date to ship It is recommended to replace your cartridges every year to obtain the best quality in water. Replacing the filters for the first time: When you make a filter change and reinstall the filters. Please note that each filter has 3 lines across. The long center line matches to a raised piece on the male end that has the small "O” ring on it. This notched piece fits into the small grove on the center piece.