10 oz., 88% cotton cotton, 12% nylon flame resistant duck; Heavyweight quilted flame resistant twill; Meets the requirements of ASTM F1506, NFPA 70E, NFPA2112, and OSHA 1910.269; Heavy-duty flame resistant brass zipper; Deep bi-swing action back; Two flame resistant lined front patch pockets; Triple-needle stitched main seams