Gevog 6" Aluminum Running Boards for 01-18 Silverado/Sierra Crew Cab (With 4 Full Size Door) Side Step Nerf Bars Item-Offered: 1 Pair 6" running boards + brackets + necessary mounting hardwares Material: Air craft grade aluminum alloy, Made from high quality material that maximizes rust and corrosion protection, great in quality Installation: Direct Bolt-On (Installation instruction is not included, Professional installation is highly recommended) Provide some side protection / brush guarding for off-road use, Slip-Resistant plastic step pads give you a more secure and easier access to the cab in any climate This item only for factory mounting holes under rocker penal, doesn't fit Diesel sub-model (with tank on passenger side)