The Mummy Mania traverse in Rocky Mountain National Park: six summits and 16 miles all above 10000 feet. The Runshade™ Top's fabric (99% polyester and 1% activated carbon) is exceptionally breathable wicks moisture and provides UV protection. 4-way-stretch shoulder panels (86% polyester 14% spandex) and a deep center-front zip vent body heat while a stand-up mini-mock neck prevents chafe and sunburn. Right rear zippered stealth pocket. Reflective heat-transfer logo. Recyclable through the Common Threads Recycling Program.Slim fit.