Channeled air cleaner base gasket fits carburetors with 5-1/8 inch necks. Designed for Moroso Air Cleaners and other brands with a straight lip. The channel provides extra protection against dust and other harmful elements, and it creates a maximum seal for carburetor airflow. The gasket is made from Buna 70 durometer material. It can be used conventionally on rolled lip air cleaner bases by flipping it over.