For road racing or when you can't wear a Fast Feet TT Shoecover, this sock saves watts.
Features
• Castelli's Fast Feet project — for maximum aerodynamics
• Foot portion based on Castelli Rosso Corsa Sock for in-shoe comfort
• Polyurethane grip strip at top to keep sock in place
• Leg portion constructed with engineered grooved Lycra® to help detach airflow
