Ideal as a base layer for added warmth, with 6.5-ounce Smart Fiber 4-Way Stretch fabric body for better athletic performance. Celliants clinically proven, mineral enhanced Smart Fibers convert body heat into infrared energy for better circulation, core temperature regulation, and increased tissue oxygen levels, enhancing endurance and speeding recovery. The 2mm hood is lined with Quick Dry Lining for fast drying performance, with a double flap neck dam, sturdy bill, adjustable SmoothSkin face seal, glued and blindstitched seams, and outer Texture Skin for excellent wind resistance.