Merino Extreme is an advanced dual layer underwear with combination of polyester and Merino wool for outdoor athletes who want the best properties of both natural and synthetic fibres. Polyester is designed for optimal moisture transport, while Merino wool has supreme insulating properties. Because of excellent synergy of two fabrics, the athlete can feel comfortable from mild to cold conditions. Material: Merino wool is one of, if not the, finest wool today, leading the pack of other conventional wools with its perfectly soft nature and fine fiber texture. You can trust our THERMOWAVE's MERINO to get the following benefits: perfect insulation, exceptional breathability, smooth feeling. During winter time, the THERMOWAVE's MERINO wool works as a perfect insulator keeping the wearer warm, while in summer periods the same remarkable wool reveals the ability to breathe easy and transfer moisture vapor away from the body, keeping the wearer cool and dry. In addition to the great insulation and breathability Thermowave's Functional Polyester is suitable for a variety of activities in chilly-to-cold weather conditions. Made from 100% functional polyester yarns, this fabric provides an exceptional moisture evaproration function. In addition, featuring a unique knitted fabric structure, Thermowave's polyester garments feature great warmth insulation, are light, soft, and have an excellent body fit. All of these benefits, coupled with very easy care, make our polyester garments a perfect choice for intensive activities in lower temperatures. All Thermowave's functional polyester garments are applied with Silver-ion finishing . Composition: 80% Merino wool ir 20% functional polyester (outside), 100% functional polyester (inside).