Fundango SEAMLESS HALFZIP Base Layer Set men's underwear is made of a technical thermal insulation material, which allows moisture to evaporate from the skin, facilitating the natural processes of temperature regulation even in case of intense physical activities, while keeping the body warm without other thick layers of clothing. Fast drying and breathability are properties that are preserved throughout the life of the material. The zipper in the neck area also helps to regulate the temperature, and the elastic cuffs fit perfectly on the wrists, keeping the warmth of the arms without bothering you in movement and preventing the sleeves from slipping upwards. The four-way elastic material and ergonomic cut give you complete freedom of movement, the seamless design prevents skin irritations, and the elastic waist area prevents slipping during activities.