Recycled polyester/spandex has a smooth face so layers slide on easily, and is peached for a supersoft next-to-skin layer Fabric wicks moisture and dries quickly to keep you comfortable Partial zip neck to dump heat and provide ventilation if you need a little cooling down Spandex adds the right amount of stretch combined with underarm gussets to maximize your range of motion Flatseam construction reduces bulk and chafing, and rolled-forward shoulder seams prevent abrasion from pack straps Thumbholes hold sleeves in place and help seal warmth in UPF 50+ rating protects against sun rays Contains materials that meet the bluesign® criteria Made in a Fair Trade Certified™ factory REI is Climate Neutral Certified; as we work to actively reduce our footprint, we measure annual carbon emissions and purchase an equivalent amount of verified carbon credits Size 1X Great Condition