Named after the legendary route in Yosemite Valley, the Astroman Short Sleeve Sun Shirt features our best-selling lightweight, stretchy, and durable Astroman fabric for long days on the wall, hiking, paddling, and backpacking. AirVent technology on the back yoke allows superb airflow and breathability, and built-in UPF 30-50+ sun protection protects skin from harmful UV rays. The Astroman's lightweight, quick-drying fabric is soft next to the skin and delivers the durability required for active outdoor pursuits. For sunny day outdoor activities where staying shaded and cool is critical, the Astroman Short Sleeve Sun Shirt is an elite performance top.