Two types of gaskets are available.
Ring gaskets which cover from the face of the flange to the inside edge of the bolts, and full face gaskets which cover the whole face of the flange including the bolt holes.
These gaskets are made of either nonasbestos oil or vegetable oil.
When ordering, specify the type of gasket (ring or full face), the pipe size and material, and the bolt hole number and size if required.