The 2-Layer Long-Sleeve Crew Shirt is made from Merino Wool, creating a thermal barrier to trap warm air. 70% micro polyester, 30% merino wool fabric is itch-free with natural odor controlling properties. ec2 Qwik-Dri Thermoregulation Comfort Technology keeps you dry by accelerating sweat evaporation. At 180g, this medium weight base layer keeps you warm and dry, while protecting you from harmful Ultraviolet rays at UPF 50+. Shirt has crew neck, saddle shoulders, ribbed trim with spandex, and flat seam construction. Lining is 100% micro polyester. Heather Grey.