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 38 cm in length, has a 116.2 squared inch 750 sq.cm blade thrust area and weighs 24 oz. 680 g. Fins are available in multiple sizes and colors.