The UnDBrief by DeFeet is made to keep you more comfortable while you ride, run, and just hang out. The UnDBrief fits closer than the UnDBoxer, which makes it appeal more to those that plan to be more active in the underwear. We developed this eco-friendly mesh fabric specifically for the UnDBrief. The result is underwear so light and stretchy you forget you"re wearing them - all while keeping you drier and feeling best right where it counts.