Selling to declutter. My son wore this, but he's no longer in club activities, so I'd be happy if someone else could wear it. The size is listed as O. ----------------------------------- The following is an excerpt from a search for "Asics undershirt O size" ↓↓↓ O Size Guide Height: 177-183cm Waist: 83-89cm Chest: 97cm - 103cm O Size Points JASPO Standard: A standard set by the Japan Sporting Goods Industries Association (JASPO), the size after L. Fit: Available in middle fit (slightly loose) or a type that fits the body more closely. ----------------------------------- I think this is the type that fits rather closely. It can be worn by men or women. A navy undershirt made of breathable polyester. - Color: Navy - Material: 100% Polyester - Size: O