H&C Flex™ offers flexible duct products for both residential and commercial applications that provide the most economical solution to your air-handling needs. H&C Flex™ uses formaldehyde-free, bio-based, environmentally friendly insulation for improved indoor air quality. Available in boxes or bags. Custom lengths available. Providing the ultimate in strength and protection, metalized polyester vapor barriers are reinforced with fiberglass scrim to provide high durability and tear resistance. The fiberglass insulation furnishes outstanding thermal protection with R-values of 4.2, 6.0 or 8.0. The metalized jacket air duct and sleeves are available with either a two-ply, black polyester core (Residential Series) or high-pressure, multi-ply, metalized polyester laminate core (Commercial Series) that encapsulate a high carbon steel wire helix.