Gasket has a 4.40" x 12.370" opening, is .100" thick with a steel shim inside to stop the gasket from distorting or splitting and is a paper laminate with silicone coating giving the racer a gasket that can be used multiple times as it doesn't stick or absorb fuel an oil.
This gasket will fit a 6-71 thru 18-71 roots blower with the small top opening.