The Avanti HC Pro includes all the wonderful features of the Avanti HC - a large hyper-channel induces thrust effect for increased performance/effort ratio, soft, comfortable ergonomic foot pocket and lateral inserts - with tri-material technology! The extra material means added elasticity when kicking, for super efficiency! Ridges on back of blade reinforce blade while optimizing pivoting geometry. Over-molding on the back rib further optimizes thrust and performance. Fins are made from thermoplastic rubber (TPR) and Tecralene. The medium sized blade (42/43) measures 15" (38cm) in length, has a 116.2 squared inch (750 square centimeter) blade thrust area and weighs 24 oz. (700 g). Fins are available in multiple sizes and colors.