They're like no undies you've ever felt, made from premium Australian Merino regarded as the among world's the finest, silkiest and softest. What's more, Merino is nature's performance fabric – inherently breathable, wicking and temperature regulating (which is why you've never seen a sheep sweat or shiver). The lightweight 4.57-oz. knit even fights odor, so you won't offend after days far from civilization. And it's comfortably stretchy, won't sag out of shape, because we've blended in 4% resilient elastane. You can even toss these base layers and briefs in the wash – no special handling required. C'mon, break away from the flock and say, "Make mine Merino!"