The Tyndale Men's FRMC Base Layer 1 Performance Long Sleeve FR T-Shirt is a 4.6 oz. FRMC® Jersey knit base layer rated 4.6 cal/cm2 (CAT 1), built for workers who need breathable, moisture-wicking, fast-drying FR coverage. It meets ASTM F1506, ASTM 6413, and NFPA 2112 (Standard on Flame-Resistant Clothing for Protection of Industrial Personnel Against Short-Duration Thermal Exposures from Fire) and is manufactured in the USA. The 4.6 oz. jersey knit uses flat-lock seam construction with excellent stretch to support movement while the shirt is worn as Layer 1. Its breathable technology moves moisture and dries quickly to help regulate body temperature. The garment is specifically identified for base-layer use, and no tested layered-system rating is specified. The confirmed rating for the M010T remains 4.6 cal/cm2 (CAT 1). CAT 1 garments have a minimum arc rating of 4 cal/cm2, and this shirt’s 4.6 cal/cm2 rating exceeds that threshold. Safety teams can use that garment-specific value when comparing the M010T with the protection required for a task. Procurement teams can also verify the 4.6 oz. fabric weight, Layer 1 designation, ASTM F1506, ASTM 6413, NFPA 2112, and US origin. Follow the garment care label for specific wash and dry settings. Properly cared for, this garment maintains its flame resistant properties for the life of the garment.