It's the planet's fastest boot, weighing in at 5.8 ounces. It owes its light weight to a SprintSkin upper with TPU support bands, a Sprint Frame outsole and a new stud shape. But like any great soccer cleat, the performance is in the details. A Goleo calf-leather vamp gives a snug fit to the SprintSkin upper. Inside the shoe are anti-slip EVA inserts. The Sprint Frame construction of the outsole uses geometry for stability. Forefoot flex with midfoot support is perfect for speed players. The F50's new TraXion® stud shape is designed for maximum acceleration on firm, natural surfaces. Wt. 5.8 oz.