To fit most pit bikes with a 30mm opening on carbs
48mm centers between mounting holes
e.g PZ30, VM26 or Molkt and many more.
This spacer and gasket act as a heat shield to aid the starting of your bike when it is hot.
The fibre gasket is used for the bottom of the inlet manifold, and the plastic gasket is used as a heat guard between the inlet manifold and the carburettor.