They are made of very high grade billet 6061 T5 aluminum These valve covers are baffled and will clear most popular rocker combinations. Will not clear stud girdles..Due to baffles There is one breather hole in each valve cover. Kit includes: (1) Pair Polished Aluminum (TALL) Valve Covers (1 Breather Hole Per Cover 1.25 Diameter) (2) Washable Open Style Valve Cover Breathers (1) Pair Rubber Steel Reinforced Reusable Valve Cover Gaskets (8) Chrome Alan Bolts & Washers. Powered by SixBit's eCommerce Solution. This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts & Accessories\Engines & Engine Parts\Valvetrain Components\Rocker & Valve Covers". The seller is "motornets" and is located in this country: US. This item can be shipped worldwide.