On its own, this crewneck keeps you warm, and when the temps really fall, it's your best baselayer for outdoor adventures. Designed to follow the contours of the body for an easy fit, and crafted for comfort and performance in 100% merino wool that's itch-free, breathable, odor resistant, moisture wicking, and thermoregulating. By Smartwool. Crewneck. Long raglan sleeves.