What Our Gearhead(R) Experts Are Saying:"I wear the Aero Race Pro 20 Sock on race days and hard training rides when every watt matters. The aero ribs are subtle but effective, and the 20cm cuff gives that sleek, pro-level look. It's light, breathable, and fits snug without cutting off circulation. It's my go-to when speed and feel both matter."When we're dialed in for a fast ride or a big day on the bike, we don't overlook the details-including our socks. The Castelli Aero Race Pro 20 Sock brings aerodynamic performance and everyday comfort to the most overlooked piece of kit. Built with raised aero ribs and a sleek 20cm cuff, it delivers marginal gains that add up over long distances and big efforts. Its nylon-elastane blend gives just the right mix of compression and breathability, keeping our feet cool and locked in when the pace ramps up. Whether we're hammering in a breakaway or holding threshold on a solo ride, this sock supports every pedal stroke with no bunching or slipping-just streamlined efficiency.