The Helly Hansen Lifa Merino Midweight men's half-zip baselayer long-sleeved shirt is ideal for all types of winter activities, such as hiking, snowshoeing, cross-country skiing or alpine skiing. It combines the insulation offered by the merino wool and the breathability provided by the Lifa® fibres.This garment is part of a layering system that provides comfort and warmth for your outdoor activities. Easy to layer, this base layer enables you to regulate your body temperature by wicking moisture away. This onion layering system is made of three types of clothing. The first layer, worn next-to-skin will provide warmth and quickly move moisture away from your skin. Then, the second layer, is the insulation or fleece, that provides warmth while also dissipating heat during periods of high output. And finally, the third layer, the shell, which is the most weather-protective layer, worn on the outside of all other layers.