I installed my keyboard tray today so I don't have a "durability" rating, but I can say it feels very solid and is exactly what I was looking for . It was easy to install and serves to free up more space on my rolling workstation. The screws provided were just the right size to attach the shelf to the rails and secure the assembled unit to the underside of my desk, even with the shelf's top rails in between. So far it looks great! (and a lot cheaper than the alternative solutions I've found)