Ideal as a base layer for added warmth, with 6.5-ounce Smart Fiber 4-Way Stretch fabric body and sleeves for better athletic performance. Celliant’s 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 & blindstitched seams, and outer Texture Skin for excellent wind resistance.New from Xcel is their drylock smart fiber 4 way stretch that provides added warmth to your hoodless wetsuit. Clinically proven, Xcels Drylock Celliant converts body heat into infrared energy for better ciruclation which translates into warmer core. A quick dry lining, sturdy bill, and adjustable seal on the 2mm hood provide powerful wind resistance and warmth to your head.