These things are pure speed. Proven at the highest level these things definitely life up to their description. When you slip these babies on you immediately feel fast. Just glancing down at them on the start line gives you a mental boost. After riding these for over a season now, I can say these are a great set of shoe covers, but remember these are aero-covers and should be wore as such, not a a foot warmer or rain cover. Another word to the wise, if you have somewhat bigger calves or legs I would suggest maybe a size up as they ride pretty far up your ankle/leg are are designed to be super tight.