The Klattermusen Men's Eir Forest Long-Sleeve T-Shirt is such a delight to wear that you won't only use it as a baselayer. Its ultralight merino wool blend feels so good that you'll wear it around town as well as in the mountains. Merino wool excels at thermal regulation, meaning it can warm you up when you're cold and vice versa, and it contains natural anti-odor properties that you'll appreciate during all your travels. Klattermusen blended silk with the wool to add durability, softness, and extra coolness in warmer weather. With seams set to the sides, this shirt is a great option for backpacking with a heavy pack. This ultralight baselayer feels best in summertime and the shoulder seasons, especially when you're spring skiing on a sunny day.