Castelli set out to make an aero sock that doesn't compromise on the things that make a great sock. Working with expert Italian knitters and state-of-the-art machinery, they created a structure that combines smooth and textured zones to control airflow and reduce drag, without sacrificing comfort or fit.

The result is a sock that stays up, feels great, and delivers aero performance equal to ribbed Lycra® cuffs, with the bonus of true everyday wearability.

• Traditional sock comfort with raised aero ribs
• Developed to provide everyday aerodynamic gains
• Durable and breathable construction
• 90% polyamide / 10% elastane mix for optimal comfort and fit
• 20cm cuff