Fast Feet Sock Size:L/XL As seen on the backs

As seen on the backs of swimmers everywhere

10-42 Compatible

52% recycled polyester

Clamp Compatibility: Includes 2 sets of clamps for compatibility with both 22

Fast Feet Sock Size:L/XL As seen on the backsCastelli's fast feet aero cycling socks are constructed with engineered grooved Lycra to help detach airflow, with the intention of improving aerodynamics for faster riding. The lower portion of the sock is based on Castelli's time proven Rosso Corsa, with the aim to provide comfortable coverage and good ventilation. Around the ankle, the make up changes to that distinctive grooved Lycra, which has a feel similar to a jersey or set of bib shorts.