I installed a pair of 14" slides. I used them on a 48 inch box. I know the seller recommends a maximum drawer size of 24 inches. However, I am satisfied with the way the guides work. They're pretty smooth. There is a slight wobble which I think can happen if the box is wider than it is deep. Easily separate the drawer side from the cabinet side. I loaded them up pretty heavily, but I don't think I beat their rating. The weight can help them run more smoothly. The instructions are not worth reading. I installed the slides beforehand so I don't really need them, but looking at them I think they're not very clear. If you're new, watch YouTube videos or something. I read a few other reviews and there were some pretty negative ones. I haven't had any of the same problems. I found a random small black piece of plastic in the bag that held the slides. But looking at the slides, I couldn't understand where he could be coming from. Everything seemed fine. Don't discount their experience but my experience was different. Maybe the seller has quality control issues - I don't know. Looking at the other slides available on Revain, they all contain some pretty emotionally negative comments. There was no clear choice; There is always someone who hates the product. I tried to go through the pros and cons and settled on these slides. I will buy more.