adidas Performance Men's 2015 Crazylight Boost Primeknit Shoe 100% Textile Imported Rubber sole boost's energy-returning properties keep every step charged with an endless supply of light, fast energy adidas Primeknit is carefully engineered to naturally expand with your foot while you run to give you a more comfortable fit and help reduce irritation One-piece sock-like construction for best fit and feel Comfortable textile lining Molded heel cap for added support with grippy rubber outsole