About this item Comfortable Base Layer: Our insulated shirt for men features dual-layer engineering with a Merino wool fabric blend that traps body heat between layers to provide a natural, chill-blocking barrier of warmth Efficient Design: Our tagless thermal shirt is equipped with convenient stay-put ribbed cuffs and a drop tail that provides coverage without restricting freedom of movement Relaxed Fit: Designed to fit loosely on the body, our men&';s thermal long-sleeve shirt boasts a generous cut, tagless design, and flat seams for a smooth, ultra-comfortable fit and feel Cold Weather Apparel: Our men&';s thermal shirt allows for minimal layering in extremely cold conditions during low- to medium-exertion activities; Perfect for casual or active wear Versatile Sizing: Our men&';s long johns are available in regular sizes from Small to 3XL