6 Diameter aluminum Tubing , Full cover aluminum bar, great in quality. Brackets, hardware, and plastic bracket covers included. Instruction will NOT be provided, professional installation is highly recommended. We are committed to resolve all issues in a friendly and satisfactory manner. All emaisl will be replied within 24 hours (Except weekends and any major Holiday).If you do not get a response from us, then please check your junk or spam mailbox. The item "For 6 07-18 Silverado/Sierra Extended Cab Nerf Bars Side Steps Running Boards" is in sale since Tuesday, September 3, 2019. This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts\Exterior\Nerf Bars & Running Boards". The seller is "oic-racing" and is located in West Covina, California. This item can be shipped worldwide.