Versachem Mega Grey Silicone is a high performance, moisture curing gasketing material that cures into a strong, silicone rubber to make formed-in-place gaskets. Maintains long term durability and flexibility, and will not harden, shrink or crack. Forms a tough, flexible silicone rubber gasket that resists aging and weathering. Works best on silicone, cork, felt and rubber gaskets. This black, waterproof, low odor formula is non-corrosive to steel, iron and aluminum, oxygen sensor safe, low volatile, non-toxic, non-flammable and OEM (Original Equipment Manufacturer) approved. Tensile strength of 275 PSI, and temperature range of -65F to 450F (continuous); -65F to 650F (intermittent). Resistant to automotive oils and fluids, Mega Grey is designed for high load conditions, with the closely spaced bolt patterns found in import engines.