Kuhl Men's Airspeed Long-Sleeve Shirt is a game changer. Hot sun, high humidity, and stifiling air are no match for this collection of airspeed shirts the AirVolution fabric. AirVolution is a woven, techincal nylon/poly blend that blocks the sun's harmful UV rays, wicks moisture and dries quickly. This shirt feels like cotton against the skin but boasts all the performance of polyester.