Men?s polo, Ralph Lauren, lightweight, cotton, and polyester blend long sleeve crewneck shirt. The torso is a lightweight thermal material while the sleeves are regular T-shirt type material. Tag size medium. Laying flat measures 26 inches shoulder to ham and 19 inches armpit to armpit. In my opinion, the fit is on the slimmer side, but it is not labeled as slim. That is just my subjective opinion.