The Arc'teryx LEAF Men's Cold WX Long Sleeve Shirt AR is a durable midweight base layer long-sleeve shirt that effectively regulates temperature in cold weather conditions. It is designed to wick moisture away from the skin, enhancing thermal efficiency and keeping you warm and comfortable. The shirt is made with A.B.M.T. 180gsm Nylon Core Spun Merino Wool, which combines the strength and resilience of nylon with the natural warmth and anti-odor properties of merino wool.