Castelli engineered Air_O Stretch fabric on body, for breathability, comfort and performance Dimpled aero sleeves Hydration pocket for 1.5l bladder Hose loops Raw-cut sleeve endings for comfort Three rear pockets Zippered security pocket Full-length YKK® zipper.Performance and aerodynamics for any terrain, with hydration pouch.Pro-level jersey designed for the rigors of multisurface racing, with a hydration pouch for when every second counts.