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)