Liang Rou Men's Stretch Top & Bottom Thin Crewneck Thermal Underwear Set Elastic closure Please choose the suitable size according to the size chart (in Product Description). 2-Piece Set Men's Thin Thermal Underwear Set (Top & Bottom). High Elastic Fabrics. 95% Modal Cotton 5% Spandex. Ultra Soft, Comfortable, Breathable and Well Adapts to the body. Great to wear alone at home or add an extra layer of warmth under your clothes