Measures: 4-15/16″ (OD) x 13-5/16″ (Length) with 2-1/8″ open holes on both top &; bottom end caps.  This cartridge is an upgrade from the C-4326, C-4325, &; C-4637 filters, but all measure the exact same size (OD & Length), they just have different pleat counts, so measure at different sq. footages.
Works on: Rainbow, Waterway Plastics, & Custom Molded Products.