FCS ARC (AM-2 Version 2) Surfboard Tri Fin Set - Medium Version 2 of the FCS AM-2 Al Merrick Set Size: Medium Performance Core Tri (Thruster) Fin Set Base: 4.55" / 116mm Depth: 4.52" / 115mm Area: 14.89" / 9608mm Sweep: 36.6 Foil: Flat