Coldpruf Men's Merino Wool Base Layer Long Sleeve Shirt - Merino wool naturally provides thermal qualities, odor resistance, high UV tolerance and flame resistance, making Merino wool the most versatile of nature's fibers. Flat seamed construction for smooth fit comfort; featuring an extended tail for secure fit and a modified yoke design for exceptional look, comfort and fit. Silk Weight 100% Merino Wool, 142g Natural Warmth Moisture Management Single Layer Jersey Knit Fabric Weather Conditions: COLD to VERY COLD Activity Levels: MEDIUM to HIGH Style: 88A