The versatile LIFA® Merino Midweight Crew Base Layer adapts to any type of cold weather. We combined a 100% Merino wool layer with our proven LIFA® Stay Warm Technology in a fitted 2-layer construction. LIFA® Merino Midweight Crew Base Layer delivers all the breathable warmth of Merino wool fibers, plus the unique moisture management properties of LIFA® fibers.