Description of Royal Robbins Extreme Expedition L/S Shirt - Women's This wrinkle resistant, lightweight fabric with UPF 40+, incorporates special fibers that channel moisture away from the body to help keep wearers dry. Grid-like construction makes this fabric highly durable and resistant to abrasions, punctures and tears. Features: Coolmax Extreme Expedition Ripstop 2.9oz, 100% Coolmax polyester UPF 40+ Wrinkle resistant Garment weight 8.5oz Dri X-treme mesh lined collar band and vented back yoke Hook & Loop secure document pockets Zip secure front pockets Button roll-up sleeve tabs Modified shirt tail with side vents