I ordered these because my cotton selection was getting faded and worn.  These are very nice with two layers of fabric used, which is soft and breathable.  I ordered two mediums, one white and one black.  Im a 34 with normal cut pants but a low rise is a 36 waist.  The order came with one med and one large, and they both fit.  I like the large better which rides lower and has a light cling feel and just a little bigger pouch.  As with the other reviewers go up one size up if your borderline or have a large package.

From time to time, When Im in the shower I asked my girl friend to grab some underwear out of my drawer and usually this black or white pair show up.  I normally wear boxer shorts.