This is an undershirt for school medical checkups. It's a size L, tank top style, with a large opening in the back for easy auscultation during internal medicine checkups. The neckline is also wide to facilitate auscultation of the chest. The buttons on the sides can be undone to open the chest for electrocardiogram (ECG) examinations. The original packaging has a school uniform manufacturer's logo, indicating it was developed specifically for school medical checkups. Although it's new and unused, there is some discoloration.