XSHANG Mens Fitness T Shirts Cotton Short Sleeve Casual Gym Tee 95% Cotton/ 5% Spandex, soft slim fit undershirt & t shirt. Original Xshang Brand, Professional Sport Tank Top and T-shirt manufacturer. Suit for casual / sports wear(gym athletic), stretch-fit. Fitness and elastic, close-fitting crew neck t shirts. PLEASE read the size chart in the detailed picture on the left carefully, not the ones by Amazon on the side of the item that you click, if you are not sure of the size, ONE SIZE UP is a good idea