With a flat inner foil

our power blades in stock have a 40mm flex rating

This is the traction pad big wave surfer and aerialist Albee Layer relies on when dropping into Jaws and sticking airs

and are widely used by pro level surfers because the integrity of the flex is maintained under immense force

FCSII Christenson Twin Fin Set 6 With a flat inner foilOverview From high performance twins to more traditional shapes, this is a perfect compliment to your twin fin. This set provides smooth and fast down the line speed. Board Types Designed to fit the FCS II Fin System. Recommended for all board types including fish, funboard and twin fin boards.