The Pace Air Long Sleeve Tee is built for high-output activities like running, fast-paced hiking, and mountain biking in warm or humid conditions. It uses Rerun Jersey, an ultralight and stretchy fabric made from 100% recycled polyester, with a superfine anti-snagging knit that wicks and dries quickly. The slim athletic fit moves with the body without restriction, and flat seams are positioned to minimize friction during extended effort.