rFOIL™ RRR is a single layer of 99.9% pure aluminum foil laminated to a 6 mil layer of polyethylene and pin perforated. This results in a house wrap that acts not only as a superior air infiltration barrier, effectively sealing up cracks or gaps in the external sheathing, but it also adds a radiant barrier to the exterior of the home blocking up to 96% of radiant heat. This results in better year round efficiency and comfort levels.