FCS II JS Tri Fins - Medium - BlackFCS II JS Tri 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 tissue inlay helps distribute the