Refrigiwear Men's Flex-Wear Base Layer Top - Long Sleeve 1/4 Zip Mock Neck, Black Flex-Wear is an extremely comfortable material that flexes and stretches with your movements. Best of all, it is very thin and lightweight, providing you with warmth without weighing you down. Versatile base- or mid-layer top that features a 1/4 zip collar that can be zipped up to provide extra warmth for your neck Extremely comfortable top with 92% polyester / 8% elastane plus 4-Way stretch, brushed inner lining Brushed inner lining also serves to trap heat, making the Flex-Wear Top perfect for colder environments or winter days in the outdoors Anti-microbial treatment provides protection from germs and mildew while anti-static finish helps you avoid annoying static electricity build-up