4 PCS Roof Box U-Bolt Clamps, Universal Metal Rooftop Cargo Carrier Rack Bolts, 85mm Internal Width Car Van Mounting Fitting Kit, U-Bracket Clips with 8 Lock Nuts - Walmart.com
Roof Box Mounting Bracket | Rooftop Cargo Carrier Rack Bolts | Car Van Mounting Fitting Kit U Brackets Installation Accessory, with 8 Lock Nuts, 2 Strap - Walmart.com
Thule Evo Clamp | Thule | United States
Roof Box Accessories - THULE Roof Boxes
Amazon.com: 4 PCS Roof Box U Bolt Clamps, Color You U Clips Rooftop Cargo Carrier Rack Bolts, 85mm Internal Width Car Van Mounting Fitting Kit for Cars, Cargo Carrier Roof Rack Bracket