Vibram Men's Speed Synthetic Running Synthetic 4mm Vibram TC-1 Rubber Outsole - Designed anatomically to give the best protection where you need it most Stretch Polyaminde Upper - Designed for a superb glove-like fit, with TPU toe caps for protection and with padded collar and topline for great comfort Sole Thickness - 4mm 2mm Eva Insole - For enhanced cushioning. Weight - 334 Grams