Naked Viking Surf Large GL Thruster Surfboard Fins (Set of 3) FCS & Futures SIZE: Large; WEIGHT RANGE: 175 lbs and over / 79 kg and over / BASE: 4.73 inch / 12.0 cm; HEIGHT: 4.77 inch / 12.1 cm; AREA: 16.12 sq inch / 104 sq cm; SWEEP: 36.5 degrees FOILING: SeriesIII - The exclusive NVS SeriesIII Foiling is designed to increase laminar flow (Hold), and decrease turbulent flow (Drag). The SeriesIII Foils work on a wider range or angle of attack which means you'll hold more speed through turns. SeriesIII Foiling designed on fluid dynamics research from NASA. FCS and Futures Compatible Fins Designed and Developed in San Diego, CA The NVS SeriesIII Foiling is the most advanced surfboard foil on the market