Craft Sportswear Women's Zero Extreme Wicking Athletic Skiing/Cycling/Bike/Training Long Sleeve Base Layer Crew: cooling/protection/ventilation/outdoor/sport/warm, White, Small 100% Polyester Imported On the outside, a hollow fiber offers insulation as well as moisture transport to the next layer Craft is the official apparel and footwear sponsor of Spartan Race Ergonomic fit and superb drying effect; a hexa-channel fiber against the skin enhances moisture transport, cooling the body down Thin lightweight and elastic fabric that is channel-knitted with two high-tech polyester fibers Flatlock seams that follow body movements On the outside, a brushed fiber offers insulation as well as moisture transport to the next layer