Polyaire Firebreak Duct Superior R2.0 - 6MFeatures: Superior Insulation Thicker insulation greatly enhances duct performance and integrity. Superior Performance The thick insulation and R2. 0 rating. Provides significant reductions in heat loss gain. Superior Efficiency Far superior thermal characteristics than lower R rated flexible duct. Superior Air Temperature Transference There is less fluctuation of air temperature through the duct which provides more even distribution of the