The Unicel C-6650 R is a compatible replacement for the following pool and spa water filter cartridges:
The Unicel C-6650 Comp. Pool Filter Cartridge is a pool filter cartridge replacement constructed with 50 sq. ft. of pleated Reemay filter media for the reduction of contaminants in swimming pool and spa water. This compatible Unicel spa filter, also known as the Filbur FC-2725, measures 6 9/16" x 19 5/8" with 2 1/8" Open top and bottom styles.