Our warmest base layer combines unique Lifa® wicking technology with merino wool’s natural warmth. The best base layer on the market uses a clever 2-layer construction to keep you dry and warm during any cold weather adventure. Our Lifa® technology wicks away moisture while merino wool creates breathable warmth.  With 65% Merino Wool and 35% Polypropylene, you get the ultimate benefits of both. Fiber content: 65% Merino Wool, 35% Polypropylene Weight: 345g FEATURES HH LIFA® Technology LIFA® Merino delivers all the great benefits of merino wool fibers plus the unique properties of technical LIFA® fibers Added shoulder fabric for back-wearing durability