Heavy-duty: Made of high-quality aluminum for superior efficiency and durability. Mounting clamp set ideal for securing truck racks, camper shells, toppers, canopies, antennas, and other applications Fixed parts: Truck clamps are used to fix all kinds of goods to prevent them from moving or loosening during driving and ensure the stability and safety of vehicles Provide greater stability: The screws of the truck roof clamp have ridges or small teeth at the top and bottom to help better fixation. You will find that they have no activities in your fixed place Simple installation: Whether you use them for the first time or often, they are easy to connect. There is no need to drill holes, and there is no need to worry about leaving traces of damage. Just fix the camping tongs on the bed, insert the screws into the designated holes, and then tighten the screws with a wrench Package: 1 set of 4 clamps as shown in pictures