"The RealTruck Backrack Toolbox No-Drill Installation Kits are designed to accommodate a standard 21"" cross bed toolbox. The toolbox sits on top of the mounting brackets allowing you to slide the toolbox forward so that bed space is not wasted. The toolbox is secured to the toolbox brackets by drilling sheet metal screws through the toolbox itself and into the top of the bracket. Drill and bolt is also acceptable. Clamp hooks that come with the toolbox are not required. Toolbox brackets are also available in 31"" length as an accessory. Backrack is a RealTruck brand. When you order an install kit or any other RealTruck Backrack product from us, you're dealing directly with the manufacturer. We guarantee all RealTruck Backrack install kits for one year. | RealTruck Backrack 21"" Tool Box Bracket Kit 30102TB"