Insta-Seal is a multipurpose cross linked butyl rubber tape that provides the ultimate in weatherproofing. It bonds to galvanized metals, aluminum, stainless steel, plastics, wood, glass and concrete.Features and BenefitsForms to irregular surfacesStays flexibleBacking prevents dust collectionUse on vent caps and roofsOne side is stickyEasy application just measure, cut and applyPrevents water from getting into holesNon-stainingPasses ASTM-E-84-40 250F (-40 121C)Resistant to water, water vapors, ozone and mild alcoholsRemains pliable for 20 years