The Castelli Aero Race 6 SS Jersey is the sixth major revision of the Aero Race Jersey, their most comfortable and aerodynamic iteration yet. Castelli engineered the first aero jersey for road racing back in 2006. Back then, aero was only for TTs and performance was mainly concerned with moisture management.  Even Castelli's aerodynamic consultants expected limited gains, so they named the jersey Split Second, though, like now, they thought even small gains were worth pursuing. In the end the gains were substantial, and they managed to revolutionize the look of the pro peloton. The Castelli Aero Race 6 SS Jersey is now the sixth major revision of their aero jersey. Each generation has become more aero and better fitting. The Castelli Aero Race 6 SS Jersey benefits heavily from CFD analysis and of wake flow in the riding position, this has guided fabric and seam placement. It also benefits from Team Ineos riders' feedback, as Castelli worked to make the jersey comfortable for their long hours of training in every possible weather condition. Castelli Aero Race 6 SS Jersey Features CFD-based fabric placement and seam construction Engineered for aero efficiency at 30 to 55 km/h Airflow shoulder construction 3D mesh back for breathability Elbow-length stretch sleeves with raw-cut edge YKK® Vislon® zipper Drop tail allows perfect pocket placement while keeping jersey fitting well at the waist Castelli Aero Race 6 SS Jersey Specifications Velocity Rev2 fabric on front and sleeve Weight: 119g