Women's Multi-colored Plaid Shirt, says sz M/L but I say S/M

100 % cotton, flannel-like 3/4 length sleeves with roll-up band no cuffs on sleeves great with jeans machine washable label says sz Large but closer to Medium - I can wear it but can't button it so, if you want to button it up, I'd say it's on the small side laid flat, pit to pit 17 1/2"