Design: Aerodynamic synthetic upper comfortably wraps and secures your foot so you can focus on the finish line Internal bonded suede: soft, on-skin-feel microfiber and suede ensures comfort for barefoot usage Seamless upper construction minimize irritations, and allows for barefoot usage Durability & Traction: Full-length, 8-spike Pebax(R) plate is the same that Usain Bolt wore during his record-breaking career Additional Details: Designed for 100m- 400m events