Patagonia M's SS Self Guided Hike Shirt Versatile, easy-care, long-sleeved shirt for fishing and travel made of lightweight, quick-drying recycled polyester ripstop with 40+ UPF sun protection. Fair Trade Certified sewn. Regular Fit * Made of 100% recycled polyester woven ripstop with 40+ UPF sun protection * Button-down collar * Full-button placket * Patch-on chest pockets with button-and-loop flap closures; left pen pocket * Midback vertical vents for ease of movement and ventilation even when wearing a backpack; shirttail hem keeps shirt in place during motion and stays put under a hip belt