When you're shivering on the start line, waiting for the announcers to painstakingly work their way through mispronouncing every name in the call ups as the rain slowly seeps through every layer of kit, the last thing you want to worry about is soggy, heavy shoes off the line and a cold squish in your toes with every pedal stroke. Keep your feet dry and turn the pedals comfortably in the dampest of weather with the Castelli Aero Nano Shoe Covers. While shoe covers have long been employed to reduce drag from ratchets and other shoe accoutrements during time trials and road races, Castelli takes things further with the Aero Nanos by fashioning them from silicone coated waterproof and windproof stretch fabric to fend off the weather. Sealed seams and a waterproof zipper bolster their water blocking abilities, while a silicone gripper holds the cuff in place to eliminate bunching and prevent seepage from above the ankle. The Aero Nanos incorporate a rubberized bottom side to increase durability, and reflective elements increase visibility to motorists in low light conditions.