Installed these 100 lb supports on our RV bed/storage. It had 80-pound uprights, but they bent and broke when the cheap hinges on the bed surface snapped, allowing the uprights to work at odd angles. The 100-pound racks definitely push harder than the 80-pound racks, and the material is noticeably heavier. . We had to reinforce the lid with additional hinges to withstand the pressure required to close it. But it doesn't close anymore! Installation Note: To remove the clips that allow the end to snap onto the ball, insert a small flathead screwdriver under the clip on the back of the end of the attachment. This will remove the ends of the clips and allow for easy sliding over the end of the bullet. There were no instructions in the packaging.