All these Thon drawers are built from heavy steel and are heavy duty, I have three of the 4U and one 2U built into the Studio Producer RTA workstation desk. All excellent kit and very reasonably priced. The function of the drawers is as good as the build quality, they very smoothly slide in and out on their runners and latch themselves shut when closed so they don't inadvertently open. They come with heavy duty locks built in and are supplied with two keys. I would recommend these drawers to anyone, for studio use or if they need to withstand the rigours of the road.