R-8 HVAC Duct Wrap Insulation rFOIL Big 8 - 4' x 50' (200 Sq Ft)EcoFoil Big 8 HVAC Duct Insulation Wrap (R 8) is engineered to limit radiant heat gain and loss while providing an airtight thermal break around residential and commercial ductwork. When all seams are taped, the wrap forms a continuous vapor barrier that helps prevent condensation and moisture related issues. For best results, we recommend sealing seams with EcoFoil Premium High Tack HVAC Tape to ensure the insulation performs as one cohesive layer.