This is the official LVFR Duty Nomex IIIA shirt. Its made of 4.5 oz 100% Nomex IIA plain weave fabric. Its Certified to meet NFPA 1975 Regulations. It also includes a panel front with hidden snap closure for easy access, two mitered breast pockets with hook and loop closure, a left pocket flap that includes a pencil/pen slot, and a fuse banded dress collar and cuffs.