Humans can't make insulation better than the one sheep grow. We've tried, but Merino wool outperforms synthetic materials for comfort, heat retention, moisture-wicking, and odor resistance. Instead of trying to one-up nature, we're working with it: Grown by sheep, perfected by technology, our Thermo collection starts with the highest quality, hand-selected New Zealand wool. We send that wool to Germany where it gets blended with just enough synthetics to create the perfect stretch and woven into yarn. We use that yarn to make our durable, ultra-comfortable Thermo Collection.