The Expedition Chill Stretch 3/4 Sleeve is the newest version of the most versatile Royal Robbins women's outdoor shirt. They've added a heat-activated, thermoregulating TempraTech mesh to the back neck panel to make this top combat hot weather and keep you dry, cool and comfortable. Added performance features include UPF 50+ protection, quick dry, wrinkle resistance, and a bit of stretch keep you sun safe on all your adventures.