FCS II Modern Keel Twin Fins Overview Upright keel template designed for traditional fish shapes. Lower sweep (rake) than most conventional, wider based keels which allows it to pivot in a really tight radius. High area and depth not only delivers a feeling of control when pushed harder on the open face, but helps to maintain tremendous speed through roundhouse cutbacks. Board Types Designed to fit the FCS II Fin System. Recommended for all board types including fish, funboard and twin fin boards Performance Glass Performance Glass (PG) fins are machine cut from layers of solid fiberglass. These fins are stiff, and are widely used by pro level surfers because the integrity of the flex is maintained under immense force, and in the most extreme of conditions and situations. Medium - Large New Sizing for Specialty Fins You may notice new size ratings for our Specialty Fin Range. Previously, all Specialty Series fins were rated an XL. To better reflect fin sizing, we now have 3 new size categories: S-M, M-L, and L-XL. Fin Base (inches) Base (mm) Depth (inches) Depth (mm) Area (inches) Area (mm) Sweep Deg° Foil M/L 6.41 162.8 5.50 139.5 25.05 16160 32.8° Flat