The Hauler Rack C-300 Side Mount Truck Cap Rack mounts directly to the cap of the truck. Hauler Racks engineering excellence and quality are available in this utility rack. The rack is specially designed for truck caps. Racks for full-size, midsize, and mini trucks are options. Crossbars that adjust to the width of the cap are included. The mounting brackets pivot to angle degree positions of 60 and 90 degrees. This allows for angled or straight cap wall installation. The Hauler Rack C-300 Side Mount Truck Cap Rack only works with caps that are flat on top.