a Versatile Base Layer Shirt Perfect for Everyday Comfort & Year-Round Layering Performance, the 175 Everyday Short Sleeve Crewe Features 100% Merino Wool Rib Fabric Thats Soft, Breathable, & Odor-Resistant. the Stretchy Slim Fit Provides Easy-Layering Performance Ideal for Any Active Adventure.Inspired by Nature, Icebreaker Harnesses the Performance Qualities of Natural Fibers to Offer an Alternative to Clothing Based on Petrochemical Synthetics. Merino is an Annually Renewable Fiber That Naturally Resists Odors, Keeps You Cool When Its Hot & Warm When Its Not, & Lets Your Skin Breathe for Comfort All Day, Every Day. Minimum Quantities Apply.