FCS II Performer Performance Core Carbon Quad Rear Surfboard Fins Two Quad Rear fins Well-proportioned template with Inside Foil Technology (IFT) for balance of drive, pivot & hold/Designed for combination of speed and Maneuverability with flow between turns Recommended for all board types; designed to exclusively fit FCS II Fin System & not fit traditional FCS Dual Plug System FIN SPECS: SMALL - Base: 3.83"/97mm, Depth: 3.99"/101mm,Area: 11.08"/7150mm, Sweep: 32.4, Foil: 80/20, FIN SPECS: MEDIUM, Base: 4.09"/104mm, Depth: 4.26"/108mm, Area: 12.63"/8150mm, Sweep: 32.4, Foil: 80/20, FIN SPECS: LARGE - Base: 4.33"/110mm, Depth: 4.51"/115mm, Area: 14.18"/9150mm, Sweep: 32.4, Foil: 80/20