The UNICEL C-2306 R is a pool and spa water filter cartridge that is the correct compatible replacement for the following filters:
The Unicel C-2306 Comp. Replacement Spa Water Filter has an outer diameter of 2 3/4 inches, with a length of 9 3/4 inches. This Unicel spa filter has an open top and bottom with both having a diameter of 1 1/16 inches. This Unicel C-2306 filter contains 6 square feet of filter media.