With the Mountain Hardwear Girl's Integral Tight a Hybrid Merino Wool and polyester fabric provides the best of both worlds. Its ultra-fine Merino Wool fibers provide softness and warmth, and the Integral's fast-drying polyester fibers are durable and wick away sweat. A MicroClimate Zoning construction places open mesh areas for breathability where you necessity it most, while an anti-microbial Complete controls odor.