XSHANG Mens Muscle Bodybuilding Workout Tank Tops Graphic Sleeveless Shirts 95% cotton 95% Cotton/ 5%. Spandex super soft and dry qucik. Lightweight, fitness and elastic bodybuilding tank top, close-fitting. Suit for casual/gym/sports(gym athletic), Stretch-fit. Original Xshang Brand, Professional Sport Tank Top and T-shirt manufacturer. PLEASE read the size chart in the detailed picture on the left carefully,if you are not sure of the size, ONE SIZE UP is a good idea