LAPASA Men's Heavyweight Thermal Underwear Top Fleece Lined Base Layer Long Sleeve Shirt M26 95% polyester, 5% spandex 260g/ Heavyweight Thermal for Super Warmth: LAPASA men's heavyweight thermal underwear tops are suitable for extreme cold and frigid temperatures when more warmth is required to regulate the body temperature. Added fleece lined is suitable for winter sports in the snow. Fleece Lined Fabric: Inner fleece fabric maintains body temperature and less friction to skin. It wicks moisture away from skin for drier and comfort. Four Way Stretch: Elastic fabric makes it comfortable and flexible. It is functional for any body movement. Draping Tailoring: provides super comfort and excellent body fit. It supports freedom to movement especially for shoulder. Binding of Neckline: Reinforced neckline is super smooth and improves good durability and stability.