Air intake internal /outer diameter: 42mm /39mm. Exhaust internal /outer diameter: 38mm/ 29mm. Full set in box and 100% brand new. Made of High Quality T304 Stainless Steel Material.All mandrel formed to ensure a guaranteed fit and performance. TIG Welded CNC Machine Flange. Direct Bolt-On Installation, Requires NO Modification. Professional Installation is Highly Recommended! This item is in the category "Vehicle Parts & Accessories\Motorcycle Parts\Exhausts & Exhaust Systems\Headers, Manifolds & Studs". The seller is "premium_autopartseu" and is located in this country: GB. This item can be shipped to United Kingdom.