This 1/4" thick phenolic riser for the Small Carter WCFB 4 barrel carb that has the 3 7/8" x 3 3/4" stud pattern and will fit other models as well. Add a little performance to your machine the cheap way, and keep the heat away from the carburetor to solve the heat soak or carburetor boiling issues. Includes free studs, gaskets, nuts, and washers.