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. This breather includes a grommet to ensure easy installation, and a replaceable foam insert. Note: Legal in California only for racing vehicles which may never be used, registered, or licensed for use upon a highway. See spectreperformance.com for CARB status on each part for a specific vehicle.