Castelli has been optimizing the aerodynamics of its cycling apparel as far back as 2006 with its first aero jersey built for road racing. Sure, skinsuits have been used for decades to shave seconds in TTs, but they all too often neglect moisture management not to mention the lack of rear pockets. Castelli's latest version of its slippery top, the Aero Race 6. 0 Full-Zip Jersey, is the culmination of everything it's learned about material and design and is distilled into its fastest jersey to date. We'll be the first to admit that aerodynamic clothing feels like chasing marginal gains, however, the jersey is optimized at the real-world speeds we often find ourselves riding (18 - 34mph) and the human body makes up the majority of watt-sucking drag on our rides. This sixth revision of its aero jersey is more aerodynamic and better fitting than ever thanks to CFD analysis of wake flow while a cyclist is in the riding position helping to optimize fabric and seam placement. The jersey also received feedback for Team Sky since it also has to be comfortable on those long training days and races.