The Smartwool M MERINO SPORT ULTRALITE SHORT SLEEVE is both soft and functional, making it comfortable and practical. It is made of a super-lightweight fabric, a blend of ZQ-certified Merino wool and high-performance Tencelâ„¢ fabric. It keeps you cool even during high-intensity activities, and its cut helps minimize chafing and blisters. In addition, it's odour-resistant, breathable and temperature-regulating, which are very useful features you'll appreciate when you're working up a good sweat. With a sporty, figure-hugging fit, this shirt will not only make you feel great, but also look great, whether you're lifting heavy weights at the gym or heading out for a hike in the great outdoors.