Merino wool isn't cheap, so that's why it makes sense to buy a top/trouser set from us here at addnature. Merino has numerous properties that make it an ideal material for underwear: it regulates body temperature, it's breathable, comfortable and doesn't stink after wearing it day after day. Therefore, it's also perfect for keeping you warm on long expeditions where you don't want to bring multiple pieces of underwear or don't have the opportunity to wash your clothes. That doesn't mean you can't wear merino underwear in everyday life; these sets are also great for frigid days when worn under regular clothes.