Scent Blocker S3 Expedition Weight Wood Shirt merino-wool;nylon;polyester Imported Merino Wool - Provides Natural Temperature Regulation & Moisture Management S3 Silver Anti-Microbial Technology - Inhibits the Growth of Odor Causing Bacteria Micro-Wick Technology - Disperse Moisture Away, Regulate Temperatures & Enhance Comfort. 1/4 Zip Chest Pocket - Provides Storage & Accessibility to The Essentials 4 Direction Stretch - Provides Superior Comfort, Fit & Freedom of Movement