The O'Brien Alpha Fin Series was built for versatility. Whether you're looking for a little extra hold on your skim-style boards or some extra stability as a trailer fin for surf-style performance, the Alpha Fin has you covered.• Fiberglass-reinforced nylon construction• Lightweight and durable• 50/50 Foil enhances stability and control while delivering a smooth feel on the water• Compatible with FCS fin boxes• Alpha 1.4" fin â 3.3 sq. in.• Sold individually Fiberglass-reinforced nylon construction 50/50 foil enhances stability & control while delivering a smooth feel Sold individually | O'Brien Alpha 1.4 Wakesurf Fin