Castelli's Endurance Pro 2 Jersey is an aerodynamic do-it-all jersey that boasts extreme comfort, carrying space, and unique fabric construction. With the use of four fabrics, we ensure we stay dry and comfortable no matter how hot the temperature, while Multifilament fabric on our back shields us from 94% of UV rays. Built for endurance riding, aerodynamics are key, so Castelli chose to incorporate the same fabrics used for pro-level race jerseys into the shoulders and sleeves.