1.Ultra Soft & WarmGood fabric machine washing freedom: 50 times machine washing temperature value is still up to 8.6C(ordinary cotton only 4c).Super soft and comfortable men's base layers like a second skin for you.2.The elastic fabric spandex used has 4-way stretch to give you flexibility to move with you and keep you warm without sacrificing your range of motion or comfort. When you're going out, you can wear this thermal underwear top and bottom under your clothes to keep you warm and comfortable in cold climates or inclement weather while maintaining flexibility in activities.3.LAYER OF COMFORTThese thermal underwear set are designed to be thin but effective at insulating body heat. The light material is not just able to retain body heat but simultaneously wick away moisture to maintain a comfortable temperature.4.SNUGOur thermal top and bottom are made to have a snug fit that ensures no bunching around your waistline or sleeves to reduce heat loss and better fit when worn under outer layers. The close-fitting style is more able to maintain body temperature and keep you warm. Our thermal underwear set has some elasticity and can stretch to fit all body type.5.3. Available in Big Size Small Up To 3X-large.Please choose the right size according to yourself