I believe the red fins that came with the iSonics were ALL bad. There was much dialogue at the time (2008-2010 more or less) about the fin problems. Now Starboard doesn't provide fins with the iSonics since everyone was buying custom fins to go with the boards.
Formula 160; iSonic 111; HiFly Move 105; Tiga 263; '85 Mistral Superlight.
Maui Sails TR 11.0; 9.2; 8.4; 7.6; 6.6; Maui Sails Switch 6.0; 5.2; Maui Sails Global 4.5; 4.0.