Seirus Innovation 8209 Unisex Fireshield Ultra-Thin Flame Resistant Sock 100% Other Fibers Imported ULTRA THIN - Sock Liner with Flame Resistant Thermax for maximum comfort and wicking COMFORTABLE - Flat seam construction and 4-Way Stretch keep your feet comfortable for all day wear DURABLE - Reinforced stitching for lasting strength VELCRO CALF STRAP - Ensures a snug fit OSHA - Visible Flame Retardant Label