Link Air Filter Section Height 20 In. Section Length 24 In. Total Length 144 In. Sections per Carton 4 Ply 3 Filter Efficiency 25 Percent Thickness 1 In. Frame Type Internal Wire Heat Sealed Inside Layers Air Flow 500 fpm Initial Resistance 0.28 In.WC Final Resistance 1 In.WC Max Temp 120 Degrees F Material Polyester Standards UL Class 900