The original hardware was 3 well nuts, which you can find at Home Depot. With 3 fine thread bolts, and some black plastic bolt caps up top. Reuse 5 existing bolts on bottom.

Some have said it's better just to use a self tapping screws on top or even a drywall anchor because it negates the need to drill bigger holes for the well nuts.

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2018 Ram 2500 6.7L Cummins 68RFE
19k miles -Bright White/Black - Big Horn Sport - Crew Cab Short Bed
2013 X5 35D (CEO's) - Born on 5/17/2013 -
82k miles - Alpine White/Cinnamon Brown/Premium Pkg, Sport Activity/Premium Pkg and Sound/20" Style 214/Running Boards