The La Sportiva Ridge T-Shirt is built around Polartec(R) Delta(TM), a fabric that combines hydrophobic and hydrophilic yarns to push heat and moisture out as the body works harder. Instead of a shirt that starts strong and gets clammy by mile eight, this one actually performs better under real heat and effort. Reinforced shoulder and back panels stand up to a loaded pack's constant rub, so the fabric outlasts the miles instead of thinning out halfway through a trip. What Our Gearhead(R) Experts Are Saying:"I wore this on a scorching, exposed traverse with thirty pounds on my back, and it was the only shirt in my kit that didn't end the day soaked through. The shoulder panels never wore thin either, even after leaning into the straps all afternoon."