Perforated 4 ft X 250 ft roll (1000 sf) breathable. Ideal for attics, sheds, warehouses, and as house wrap Double-sided 99.9% PURE reinforced ALUMINUM that blocks 97% of the radiant heat in summer and winter Industrialized strength with woven polyethylene scrim for tear resistance. Cannot be torn or ripped Passes required ASTM fire test (E84 using E2599 mounting method) for building materials Exceeds required ASTM Water Vapor Permeability (Breathability): 8.5 perms (ASTM 96-00) Super Shield Reflective Insulation is a 5-layer reflective energy-shield. It’s two outer layers of 99% aluminum foil reflect 97% of radiant heat. Each layer of foil is bonded to a tough layer of Mylar and has an interwoven nylon scrim for extra added strength. It's so strong it's virtually impossible to tear! It also has a Class 1, Class A fire rating! You’ll find that hot and cold spots in your home are eliminated summer and winter. You’ll find yourself enjoying greater comfort in your home. And, since it doesn’t use energy to increase your level of comfort, you’ll have lower utility bills. How It Works!!! As much as 83% of the heat gain in the summer takes place through the ceiling and roof. SuperShield Reflective Insulation reflects the sun's heat before it can penetrate your home. You will use less air conditioning to keep your home cool and comfortable all summer long. According to the Department of Energy, homeowners can expect up to 45% cooling savings depending on the climate, current amount of insulation in the attic, and household energy use. Many of our customers have experienced higher results, but these results have not been verified by a third party.