Meet Your Essential Layer for Every Mile. Engineered for the athlete who faces sun, sweat, and distance. On a scorching afternoon ride, its quick-dry fabric manages moisture so you stay cooler. During a high-altitude hike, the tightly knit design adds a layer of sun-smart coverage. As a barely-there liner under your climbing helmet or cycling helmet, it prevents chafing without adding heat. This is the no-fuss, high-function piece designed for your longest adventures and hardest efforts—because your gear should work as hard as you do.