Made from fuel resistant cork like original. This gasket is specific to 1967 - 1968 Cougars. We finally found the correct gasket with correct hole placement (our other version which is good for Cougar AND Mustang has five holes, so basically you would have to drill through the cork just like they did in the Dearborn and San Jose factories).
Here's a good tip! Ken Stein gave us this one...
Install two of these gaskets and your gas cap will not scratch your paint. Original gas caps will always scratch the paint without shimming the filler neck out with the use of a second gasket.