Flexible Duct, For Nominal Duct Diameter 8 in, Wall Thickness 2 in, Maximum Temperature Rating 180 Degrees F, Minimum Temperature Rating -20 Degrees F, Insulation Value R 6.0, Color Gray, Overall Length 25 ft, Duct Material Fiberglass, Jacket Material Polyester, Fire Rating Flame Spread: 25 Max; Smoke Developed: 50 Max, Maximum Pressure Rating 6 in wc, Maximum Air Speed 5,000 fpm, Vapor Transmission 0.6 Percent