SUNZONE Men's Long Short Sleeve V-Neck Crewneck Slim Fit T-Shirts Muscle Undershirts 95% cotton/ 5% polyester Imported Please note that the size of package is one size smaller than the tag on shirt, because it is Asia standard, and the size of package is consistent with the size chart on Amazon.com. e.g. If you order a medium and will receive a large These stretch T-shirts have V-neck and Crew-neck two styles, long sleeve and short sleeve for spring, summer, autumn, winter all seasons, and perfect as a fasion casual T-shirt or a undershirt Slim fit style and one size smaller than normal, make sure select follow the sellers size chart(a drop down list ) not the automatic one from amazon Amazing quality, ultra comfortable, slim fit and muscular stretch well Machine washable