FCS II JS Performance Core Carbon Tri Surfboard Fins - Large/BlackThe FCS II JS PC Carbon Large Tri Surfboard Fins. Jason Stevenson's 'JS' shaper fin updated for 2023. Great for surfers looking for a fin that'll feel dependable in bigger waves, but still want the ability to release the tail and surf progressively in smaller waves. Overview: All new construction has enabled us to produce the most responsive JS fin to date. AirCore reduces weight and creates more stiffness in the bottom 2 3 of the fin. The carbon