M-Ke Thermaflex Flexible Hvac Duct - 4 Inch Diameter R4.2 - Pkg Qty 2 0557-0400-0001-10

Thermaflex M-KE HVAC ducts have a vinyl coated spring steel wire coil construction that is ideal for low, medium pressure heating and cooling environments.

These highly efficient flex ducts feature a core that is bonded to the steel wire coil to support the fiberglass insulation. Duct insulation is available in three different R-values for varied thickness: R-4.2, R-6.0 and R-8.0. The acoustically rated, polyethylene inner liner on these HVAC ducts eliminates noise and easily expands. Spiral ducts are mold and mildew resistant. Temperature range is from -20F to 200F and -20F to 250F intermittent. Inner core is self-extinguishing. Ducts measure 4-20" in diameter. Greenguard certified. 10 Year Limited Warranty.