The OSI HM270 Construction Silicone Sealant is a one-part RTV sealant designed for sealing and glazing. It cures at room temperature upon exposure to moisture in the air providing good tensile strength and excellent adhesion, usually without the use of a primer, to most nonporous building materials. OSI HM270 easily withstands temperature extremes from -60°F to 400°F without adverse effects. This sealant from OSI will work with sealing skylights, solar panels, ventilators, aluminum siding and windows, heating/air conditioning units, duct work, recreational vehicles, and other glass, plastic or metal assemblies. Features Designed for glass, metal, and plastic Water resistant Skins in less than 10 minutes, and is tack free in 25 minutes Very flexible with up to 25% joint movement Extrudes in any weather condition, making it a great year round caulk