These Mr. Gasket Ultra-Seal III intake manifold gaskets are made from a high-density material that combines a custom-engineered copolymer binder system, which holds fibers and fillers together, with 100 percent synthetic fiber and high-temperature fillers to produce a uniform, high-strength composite sealing material. This material delivers excellent sealing properties for oil, fuels, and coolant at low flange pressure (clamp force), along with high crush resistance for continuous use up to 350 degrees F and intermittent exposure up to 650 degrees F. Made from high-density, high-tensile strength and high-temperature gasket material, Mr. Gasket Ultra-Seal III intake manifold gaskets deliver excellent sealing properties for oil, fuel, and coolant. They also release easily and will not stick to mating surfaces when you're disassembling an engine.