For Chevy Silverado/GMC Sierra Extended Cab 3" Stainless Steel Side Step Nerf Bar Running Board (Black) Built From Durable, Rust-Resistant, Powder Coated Mild Steel Large Slip-Resistant Step Pads, 3" Diameter Steel Tubing High Strength Mounting Bracket; Holds up to 500 lbs Vehicle Specific Mounting Brackets Included No Drill Installation / Bolts Right to Factory Mounting Points 2 x Mild Steel Nerf Step Bars Mounting Bracket Hardware as Shown in the Picture Above 99-16 GMC Sierra Extended Cab 99-16 Chevy Silverado Extended Cab Tubing Diameter: 3&#034; Materials:Mild Steel / ABS Plastic Style:Round Tubing Surface Finish:Powder Coated Built From Durable, Rust-Resistant, Powder Coated Mild Steel Large Slip-Resistant Step Pads High Strength Mounting Bracket; Holds up to 500 lbs Vehicle Specific Mounting Brackets Included <span class="a-text-bold">Easy Installation </span>-Easy, no-drill installation bolts right to factory mounting points in less than an hour (most models). <span class="a-text-bold">Importance of Step Bars Practicality</span> -Step bars serve two main functions. The most obvious function is to serve as a step. This is especially important for taller trucks.Protecting vehicles from various forms of road debris is a second function of step bars.Another added benefit of step bars is that they can help to keep the interior of your truck or van clean. <span class="a-text-bold">Professional</span>-Our professional technicians do heavy research and development in testing car applications and fitments for our products.