It's a size M. I bought it new, but it didn't fit, so I'm selling it. It was only tried on and is almost unused. TIGORA Baseball Practice Cap M 55-56cm 1,499 yen (tax included) A classic practice cap that's great for training sessions. Features a brim stiffener to prevent deformation. Function: Sweat-wicking and quick-drying (this function applies only to the sweatband.) Quickly absorbs, diffuses, and releases sweat. Color: White Thank you for looking.