Extang Tool Box Tonno Truck Bed Tonneau Cover | 32720 | fits Ford Super Duty Short Bed (6 1/2 ft) 99-16 L-Channel Rail Bridges the Toolbox-To-Tonneau Gap For Perfect Fit L-Channel Rail also provides a seal against the box Toolbox Tonneaus Fit Most Standard Size Toolboxes, 18-20" Exclusive And Patented All-Climate Tarp Design Adjustable Snaps and Bows For Easy Use In Cold Weather