The Unicel C-4601 R is a compatible replacement for the following pool and spa filter cartridges:
The Unicel C-4601 Comp. Pool Water Filter Cartridge is a replacement pool filter cartridge with 16 sq. ft. of media area that traps contaminants in pool & spa water in its sharp pleat folds. This compatible Unicel pool filter, also known as the Filbur FC-3745, measures 4 3/4" x 18" with a 1 1/16" Open top style and 2 3/8" Open bottom style.