Overview for Gray Flex 4-4GF-6
Gray Flex's models 4GF(R-4.2),4GF-6(R-6.0),and 4GF-8(R-8.0) are tested in accordance with U.L.181 and approved for use as a Class 1 air duct material. Jacketing is printed with certification label, foot markers, size and performance data every 24-(Foot markers every 12 inches). It is jacketed with a scrim reinforced metalized polyester vapor barrier. The airtight core is our exclusive patented, reinforced inner liner. Fiberglass insulation is a minimum of 1 1/4 thick for 4GF, min. of 2 inches for 4GF-6, and min. of 2 5/8 for 4GF-8.