The N-Ferno 6436 Long Sleeve Lightweight Base Layer Shirt is designed for comfortable warmth in mild to cold conditions. Made with lightweight and breathable stretch fabric, it is a great base layer shirt for keeping workers warm without overheating during strenuous activity. The 180 g polyester-spandex performance material provides warmth without the constricting or bulky feel often found with heavyweight base layers. The fabric is smooth and stretchable for easily layering under sweatshirts and jackets, plus a long tail for full coverage. Unlike other base layers, this shirt is designed to sit slightly looser on the skin to enhance breathability and mobility while also providing an air gap for additional insulation. Raglan sleeves with wider underarms also make for full range of motion. Featuring moisture-wicking technology and an anti-odor treatment to keep workers comfortably fresh, dry and warm all day.