Diameter 101. Please choose the thickness: 0.8mm or 1.0mm. Shown picture is an image. Detail: High performance PWR Heavy metal Gasket is proved in the world. Fuel burns at high temperature of more than 2000℃ and high pressure of 120-150 kgf/c?instantaneously in a combustion chamber of a tuned up engine. Under these conditions, a cylinder head gasket must shut off combustion gas completely and seal passages that carry oil and coolant. As turbocharged vehicles with highly powered engines are popular now, head gaskets with grommets are widely used to seal high pressure of combustion gas. Grommets in PWR Heavy Metal Gasket are designed to have surface pressure of 800-1000 kgf/c?, and beads on the outer frame of a grommet are second sealing to completely prevent instant gas leak caused by knocking. Likewise, grommets coated with molybdenum prevents scratching caused by a cylinder head and a cylinder block, and nitrile gum is used for over the gasket in order to keep high sealing capability.