A lightweight and breathable baselayer fleece for high-exertion activities in cold conditions the Patagonia R1 Air Men's Zip-Neck is quick drying and technical fabric. Built for versatility in cold weather the seams have been placed off the shoulders for pack strap comfort, and a half-zip neck with high collar allows you to vent when you need to, zip up for coverage when you’re cold. 100% recycled polyester jacquard fleece this uses hollow-core yarns to create a unique zigzag texture designed to wick moisture, dry quickly and be nicely breathable for high-output activities out in the cold. Slim fit for next to the skin comfort, size up if you are between sizes or prefer a looser fit.