Part of Carharttâ€™s Flame-Resistant protective clothing line, the FR Twill Shirt features 7-oz. INDURAÂ® UltraSoftÂ®, a blend of 88 percent cotton and 12 percent tenacity nylon. The material provides superior abrasion resistance while offering excellent comfort and durability. The long-sleeved, relaxed-fit shirt has an APV rating of 8.2. Carhartt, Inc., Dearborn, MI.