The revolutionary design of the Oceanic Manta Ray fin was inspired directly from the shape and bio-mechanics of marine animals. By combining three different materials to simulate bone, tendon and fin, we've created a blade design that provides maximum power, speed & efficiency while also remaining extremely lightweight & durable. Of course, it's not all nature's technology, we added some of our own as well. Our new soft-pad heel spring strap has a unique ergonomic finger-loop that makes getting these fins on or off in any situation a snap.