FCS K2.1 Performance Core Surfboard Tri Fin Set Color - Smoke Tri Fin Set - (3) fin set K-2.1Side Fin Stats: Base - 4.31" , 110.0 mmDepth - 4.50" , 115.0 mmArea - 15.25 sq. in. , 9824 mm2Sweep - 32.0 K-2.1Center Fin Stats: Base - 4.31" , 110.0 mmDepth - 4.50" , 115.0 mmArea - 15.25 sq. in. , 9824 mm2Sweep - 32.0 Performance Core Fin: Performance Core (PC) material and construction is designed to deliver the feeling of a traditional glass fin with the added performance of reduced weight.