18″ x 18″ Mounting Braces Provides sturdy and secure mounting for Dee Zee Underbed Boxes and Side Step Boxes. Constructed of heavy duty steel. Powder coated black to help resist corrosion. Heavy duty C-channel design provides superior strength. Mounted at each end of the box, these brackets and hardware provide maximum support from underneath. Required for all Dee Zee Underbed or Side Step Boxes.