Additional Drifire Strong Knit Long Sleeve T-Shirt features:, Arc Rating: 8.6 cal/cm², CAT 2, Compliant to NFPA 70E, ASTM F1506, Lightweight 6.5 oz. Strong Knit fabric, Inherently Flame Resistant, Performance fabric wicks moisture, dries fast, and controls odors, Ribbed collar maintains its shape, Tubular form - no side seams!