Replacement Cartridges Measuring Replacement Pool Filter Cartridges Carefully measure the outside diameter (O.D.) of the top cap and the total length of the cartridge. Note that a measurement of 5" might actually be 4-15/16", so you may look at more than one category when the dimensions are right at the inch. Can't find your replacement pool filter cartridge? Call us at 1-800-301-3945 for one on one customer assistance. We have over 400 sizes in stock! Shop for Replacement Pool Filter Cartridges:

2IN To 2-7/8IN O.D.	4IN To 4-15/16IN O.D.	5IN TO 5-7/8IN O.D.
6IN To 6-7/8IN O.D	7IN O.D.	7-1/8IN TO 7-7/8IN O.D.
8IN TO 8-15/16IN O.D.	9IN TO 9-15/16IN O.D.	10IN To 10-7/8IN O.D.