?FITMENT?This roof box u bolt clamps is suitable for most cars on the market, can be used for up 85mm(3.34 inch) width and 40mm(1.57 inch) thick luggage rack. ?HIGH-QUALITY MATERIAL?u-bolt clamps using galvanized steel material, durable, good alkali resistance, acid resistance, corrosion resistance, strong temperature resistance. ?FEATURE?This product has a rubber gasket and a plastic back plate?which can protect your car from scratches to the greatest extent, and can increase friction to improve overall stability. ?EASY TO INSTALL?: No need to drill and install directly. Accurate mounting size and long-enough bandages, suit your roof box and daily opening and closing box. ?PACKAGE INCLUDED? Roof box rack mounting fitting U-Bolt clamp kits included 4pcs galvanized U bolts, 4pcs plastic backplane, 4pcs rubber gasket, 8pcs heavy lock nuts, 2 bandages?1 Hole Sealing Sticker.