This versatile merino base layer is a true all-season tee. Merino is an active fiber, so it will help you stay warm in cold weather while keeping you cool in warm weather. And with its natural elasticity, you'll feel comfortable all day no matter what you're doing. The benefits of merino are plentiful: it's biodegradable and renewable for lessened environmental impact; wrinkle- and UV-resistant for long-lasting low maintenance; and naturally breathable for comfort.