carburetor cap, 5-1/8" neck Keeps dirt and foreign materials out of the carburetor during storage, transportation and down time at the race track. This carburetor cap is injection molded for strength and durability and is made from hi-density polyethylene to resist gasoline. Fits carburetors with 5 1/8" diameter necks and comes complete with necessary mounting hardware. Cap is colored bright yellow, carburetor not included.