The Mountain Hardwear Women's CoolHiker Short Sleeve T Shirt is literally the coolest technical hiking tee on the market. Cool.QZERO technology on the back and sides of the CoolHiker T actually lowers the temperature of the fabric when you start sweating. Polyspandex blend offers the feel of cotton but dries quickly and will stretch with you. The anti microbial finish eliminates odor, UPF 25 protects you from the sun. Body constructed of 96% polyester, 4% elastane DryTouch Spun Poly Jersey Side panels constructed of 96% polyester, 4% elastane Cool.Q ZERO DrySpun Jersey Cool.Q ZERO provides an immediate and ongoing cooling sensation Wicking, fast drying fabric UPF 25 sun protection Antimicrobial finish controls odor Flat lock seam construction eliminates chafe Active fit Avg. weight: 4 oz. Avg. length: 25 in. Import.