Vibram FiveFingers KSO Evo Running Shoes Rubber Abrasion-Resistant Stretch Nylon and Breathable Mesh Upper - Prevent detritus from infiltrating the shoe whilst allowing air to permeate the interior, promoting a cooler, drier and altogether more pleasant environment Quick Lace Toggle - Allows the wearer to tighten the shoe with a single tug. Non-Marking 3.5mm Vibram TC1 Peformance Rubber Outsole - Razor siping and a zig-zag pattern deliver optimal traction on an array of surfaces. 2mm EVA Insole - Delivers additional cushioning, protection and comfort. Anti Microbial Drilex Sockliner - Promotes a clean, dry environment free from bacteria and unpleasant odours.