GX Natural Glass Flex Side Fin Set FeaturesXXS side-bite set designed for performance longboards and SUP’s. This popular side bite template has a curved trailing edge, flat foil and subtle flex in the tip. Glass Flex Adds stability and control through turns when used with a 2 + 1 set up. A wide range of conditions from beach breaks to point breaks. Performance longboards, SUP’s and Hybrids.