Icebreaker has the world's best merino wool layering system with a reinforced core and increased burst of strength. Our men's base layers and merino thermals feature only the world's finest merino wool, sourced from New Zealand. Merino wool makes for the best base layer due to its moisture wicking properties and industry-leading breathability – not to mention its luxuriously soft feel. Designed to keep you comfortable in even the most extreme weather conditions – hot or cold – our merino thermals are also odour resistant, so you'll stay fresh after a long day exploring the mountains or a hard workout at the gym. Stock up on our different styles of wicking base layers including wool long underwear and long sleeve and short sleeve tops. Wear them for running, backcountry ski tours, mountain biking and more. Pair your merino base layer with our men's fleece jackets and vests to create an extra-warm layering system.