JEGS Valve Cover Grommets are designed to work in specific applications to insure a positive seal and prevent leaks. Made from durable neoprene they are also designed to withstand the varying temperatures and chemicals an engine may see. The valve cover plugs can be used as a plug or the bottom can be cut off for use with a breather. Our baffled grommets are cylindrical and foam filled for use with roller rockers or where a traditional large metal baffle is not practical.