【Fitment of Roof Rack Clamps】Roof box u-bolt clips are suitable for most cars, van cargo carrier roof box on the market. Inner width 82mm/3.23in, width from center to center of screw thread 90mm/3.54in, diameter of screws is 7.5mm/0.3in (M8). Can be used for luggage racks up to approx.40mm/1.57in thick, 80mm/1.96in width. Not suit for Thule Car Rack. PLEASE CHECK IF THE DIMENSIONS MATCH BEFORE PURCHASE 【High Quality】Our u-bolt roof rack clamps made of stainless steel and plastic, wear-resistant, temperature-resistant, not easy to rust, not easy to break deformation, durable, long service life, light weight accessories, occupy little space, easy to store in the room or car. 【Good stability】The rubber gasket and plastic backing plate are effective in increasing friction, reducing vibration, improving overall stability and protecting the cargo box's contents from violent shocks.2 nylon straps to keep the box's contents safe. 【Easy to Install】Easy to install, accurate installation size and long enough bandage to fit your roof box and daily opening and closing box, the set includes 4 stainless steel U-bolts, 4 rubber washers, 4 back plates, 8 lock nuts and 2 bandages 1 hole sealing stickers. 【Functional Racks】Stabilize the roof box and avoid dropping it during driving. Rubber gasket and plastic backing plate can protect your car from scratches, increase friction, improve the safety of the vehicle, help smoothly through potholes, mountain roads, slopes and highways, etc.