Description of Royal Robbins Coolmax® Extreme Expedition S/S - Women's A staple of any hot-weather outdoor wardrobe, the Extreme Expedition Short Sleeve will keep you comfortable no matter where you go or what you do. Trekking in Arizona canyons, skidding down scree or getting caught on cactus? Tough 2.9-oz. Ripstop fabric resists abrasions, punctures and tears without wincing, compresses tightly to take less space in a bag and denies wrinkles. Treated with MCS Blocker® this shirt also acts as a UPF 40+ sunblock. The back is vented in two places, one mesh lined, one zippered, while Coolmax moves moisture away from your skin, keeping you cool with a combo punch of great airflow and ultra-rapid drying. High tech performance in fantastic colors and fashionable design? It could only be from Royal Robbins®.