Excellent Flexibility For Any Movement --- The mens thermal clothing is designed with four way stretch compression for your freedom of outdoor activities, never have bound feeling. Flat lock will prevent chafing and irritation of skin. Check the size chart of the last picture to select the appropriate size *The set is designed for outdoor sports, there is NO OPEN FLYING on the pants* Slim&Light But Keep Warm In Winter --- There are a long sleeves shirt and pants in package. Theyre really light, soft and comfortable, especially for keeping warm in cold conditions. Ensure that the thermal long johns for men will bunch around your waistline or sleeves and reduce heat loss. Instantly Absorbing Sweat In Exercise --- The thermal fitness shirt for men is made of moisture wicking and breathable fabric, which will absorb sweat and dry quickly in exercise and keep away from clammy feeling, provide a enough comfort and warmth when you play sports in cold weathers. Feel Free To Wear Outside Or Base layer --- The men's gym shirt is good to wear at home or as a base layer under your coats, it also will warm you as comfy pajamas on cold nights. Cold weather mens thermal gear is perfect for active sports like hiking, cycling, snowboard, skiing, military& tactical games, hunting and fishing.