The Unicel C-6601 R is a pool and spa water filter cartridge that is the correct compatible replacement for the following filters:
The Unicel C-6601 Comp. Pool & Spa Water Filter has an outer diameter of 6 inches, with a length of 9 3/4 inches. This Unicel spa filter has a closed top with a semi-circular handle, and an open bottom with a diameter of 1 7/8 inches and with slots. This Unicel C-6601 filter contains 25 square feet of filter media.