The Unicel C-4975 R is a compatible replacement for the following pool and spa water filter cartridges:
The Unicel C-4975 Comp. Pool Water Filter is a pool filter cartridge replacement constructed with 75 sq. ft. of pleated Reemay filter media for the reduction of contaminants in swimming pool and spa water. This compatible Unicel spa filter measures 4 15/16" x 20 1/8" with 2 1/8" Open top & bottom styles.