I'm not sure of the size as there's no label, but my middle school son wore it. The chest mark has peeled off (see photo). The number on the back mark has been erased with a marker (see photo). It will be shipped in simple packaging. Thank you for your understanding. Sleeveless red shirt, perfect for fitness. - Brand: Under Armour - Color: Red - Design: Sleeveless Thank you for viewing. Size...M to L Size...M