The warmest merino in our lineup, the Merino Expedition Tube leverages the natural performance of merino wool. Built with 230 GSM Nuyarn® merino wool, it’s soft against your skin and durable enough for season after season; it's ready for wherever winter takes you. Nuyarn® is a twist-free spinning technique that amplifies the natural performance of merino with natural odor resistance, faster drying, greater stretch, improved thermal retention, and increased durability. The result is a warmer, tougher merino tube built for summits, storm laps, and winter expeditions of any kind.