18"W x 25ft. Insulated Flexible Duct, R 4.2, ATCO, Mfr# 13002518

Flexible Duct, For Nominal Duct Diameter 18 in, Wall Thickness 1.25 in, Maximum Temperature Rating 180 Degrees F, Minimum Temperature Rating -20 Degrees F, Insulation Value R 4.2, Color Silver, Overall Length 25 ft, Duct Material Fiberglass, Jacket Material Metallized 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 0.05 Percent