Castelli Women's Aero Pro 8S Jersey The Castelli Women's Aero Race 8S Jersey is designed to save you hard-won watts. When the decisive moments of a race are decided, you can be confident you're not wasting efforts to overcome unnecessary drag. With 80% of drag coming from the body, the Women's Aero Race 8S is engineered to be as slippery through the air as possible. Computational fluid dynamics (CFD) has allowed Castelli to place the sleeve seams precisely to reduce drag as speeds increase. The shoulder fabric also contributes to drag reduction, with Castelli claiming a 6% savings in CdA at race speeds - watt savings that could be the difference between making the race-winning break and winning the race to the finish line.  When working hard, the lightweight and stretchy body fabric gives a body-hugging and comfortable fit while optimising moisture management. Three rear pockets keep your nutrition within easy reach and an elastic waist provides pocket support and a smooth finish. With a decade of knowledge and innovation distilled, Castelli's fastest women's cycling jersey just got faster.