From the first two sets ordered, one of the ball joints failed and had to be returned. The replacement was dispatched the next day but was not manufactured correctly. The plain bearing was on the wrong side of the metal hold-down devices. Since my project had been on hold for a day, I simply used a hammer and punch to push the brackets in, moved the guides into place, and pryed the brackets back up with a small screwdriver. It worked fine after that. It's either a good product but hard to find 10 inch slides.