Allstar 5-1/8 inch Mounting Diameter 2. 5 inch Tall Standard Model Spun Aluminum Carburetor Hat is a standard model with a 5-1/8 inch mounting diameter. The carb hat is 2. 5 inches tall and is made from quality machined aluminum and features a sealing o-ring. The aluminum carb hat helps to keep the carburetor safe when the air cleaner is removed. It is backed by a 90-day limited factory and sold individually.