ESP Low-E™ House-Wrap does more than simply stop drafts. A pure aluminum facing is heat bonded to one or both sides of closed cell polyethylene foam, then the product is 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 an insulation to the exterior of the home blocking up to 97% of radiant heat. This results in better year round efficiency and comfort levels.