Surf Eclipse Accessories Fin System: All our fins are made out of Fiber glass honeycomb. The reason for this is that it makes them light and strong. We do not make plastic fins as we want your board to perform like what your shaper has designed it to. Our fins are compatible with FCS and Future boxes. Check out our prices and you will see that they are much better value than the other fin companies. We have FCS and Future Compatible Fin templates that are similar to the other companies.