Introducing the Men's Liberty Flex Bib Overall. It is made with all the classic Liberty bib features, such as the signature green zipper and iconic pocketing system. Now, it comes with added flexibility and durability from the 98% cotton / 2% spandex flex denim, which has been stone-washed, tinted, and hand-sanded for a vintage look and feel. With the flex bib, you'll experience all-day comfort while you work.