My fiance is XL in polos and 2X in button down shirts (as shown here). Here is my size. However, 2X is too small for him. He has several other buttons that are twice his size and fit him perfectly so this brand is not true to size. 2X is more like L. And material. as if it were a reusable grocery bag. Or raincoat material. Not what I expected from the up button. I just know if he could put it on it would make the same sound as a raincoat when the fabric rubs together. Not impressed and would not recommend.