In just over a year, the KSO has become our most popular model for men.Featuring a thin, abrasion-resistant stretch nylon and breathable mesh upper that wraps your entire forefoot to "Keep Stuff Out."A single hook-and-loop closure helps secure the fit.A non-marking 3.5mm Vibram TC1 performance rubber sole is razor-siped for a sure grip, and a 2mm EVA midsole enhances plating protection and comfort.