A secret, unique formula ensures that the Fulling Mill Copolymer has a clear non reflective finish, making it almost invisible in the water. LB Diameter Code 2.2. 10 F-FMCP50-2.2 3.1. 12 F-FMCP50-3.1 4.2. 14 F-FMCP50-4.2 6.4. 18 F-FMCP50-6.4 7.9. 20 F-FMCP50-7.9 9.5. 22 F-FMCP50-9.5 12.8. 26 F-FMCP50-12.8