Description Castelli's gossamer-light wind shell acts like an invisible shield that provides near weightless protection against the elements. The magic comes from the cut and the stretchy mesh fabric on the back which allows for a close-to-body fit without feeling tight. The Aria effectively blocks wind without any overheating concerns and fits into its own pocket (as well as your smallest back pocket). Best for conditions of 54 to 68 degrees. Product Details • Front fabric: ultra lightweight, windproof, woven microfiber • Rear fabric: striped mesh with high degree of stretch to avoid fabric flapping in the wind • rear pocket • reflective piping for visibility • highest quality/lightest weight YKK Vislon zipper