A high performance cold weather base layer shirt, the Icebreaker men's merino wool long sleeve Mondo Zip Bodyfit active base layer is simple and natural. The lightweight material has ultra fine fibers so it feels soft and won't itch. Icebreaker merino wool resists odor naturally so you can wear it for days or even weeks without washing it û and when you do, it's easy care: machine wash cool and line dry. This material also offers sun protection (UPF 50+) and resists static electricity build up so it won't cling. Icebreaker Merino wool is perfect for keeping New Zealand high mountain sheep comfortable and happy, insulating to warm them in the winter, and breathing and wicking to cool them in the summer. Not surprisingly, merino wool works like this for you too. The men's Icebreaker Mondo Zip is perfect base layer for mild to cold weather activities.