Categories Spunstrand New ICC-ESR-1681 Listing For Non Insulated Duct & R-4, R-6, R-8, R-10, R-12 Duct Post author By spunstrand Post date December 8, 2023 ESR-1681 Final Report ← Spunstrand Thermal Insulation Manufacturer License # T1494 → New Resin Product Unveiled!