Cressi xl men's 11 to 13 Pro Light is more powerful, and is easy to use than any fin on the market. The unique polypropylene blade material provides a variable flex that adjusts during the kicking cycle. The blade is extremely flexible and has snap requiring less kicking effort. The side stringers that extend all along the blade and two flaps situated along the end of the blade itself make the fin very directional. Cressi is the first company to recognize the performance value of the foot pocket. The Pro Light's foot pocket is made of a comfortable elastomer material and is computer designed to give ideal transmission of leg-fin thrust the blade becomes a true extension of your leg. The blade originates from the upper part of the foot pocket, with a 20% increase in useful surface area compared to a traditional fin of the same length.