The Carhartt Flame-Resistant Duck Bib Overall is NFPA 70 compliant and made with 13 oz. 100% cotton FR duck. This bib features a high back with FR elastic suspenders and high-temperature nylon center-release buckles. The chap-style double front adds durability and increases the thermal performance. The front is equipped with a brass fly zipper and Nomex® zipper tape.