Push-in Valve Cover Breather Black Coated Polished Ball Milled Alloy, features an internal baffle to prevent oil splash and provide superior ventilation.Supplied with internal replaceable Pcv Valve. Designed for 1-1/4 inch breather holes, with a 1 inch outside diameter neck. Ideal for use in conjunction with the grommet part number 41901, this breather includes a replaceable internal foam insert. Manufactured using high quality materials, this breather cap’s Alloy construction ensures it performs as well as it looks.