Spectre Oil Breather Cap 3/4in. (Push-In)Spectre's 3 4 inch push in chrome valve cover breather has a chrome plated housing and features an internal baffle to help prevent oil splash and provide superior ventilation. This product is designed to work with valve covers that have a 3 4 inch to 1 1 4 inch breather holes. We recommend using our 5339 or 5333 grommet kit when used for 1 1 4 inch valve cover holes. Note: Legal in California only for racing vehicles which may never be used,