Aqua Lung Express Full Foot FinsWith the efficiency of the Express, you can stay submerged until you forget the rest of the world exists or you run out of air. Whichever comes first. Its armadillo hinge of grooved elastic material at the base of the blade absorbs energy during the power stroke and releases it at the end of the kick cycle. You'll go farther with reduced strain on your legs and feet. Features: Armadillo Power. Our Armadillo Hinge at the blade base absorbs energy on