I ordered this tray to sit in the top drawer of a portable file cabinet at work. We have shared work spaces so I needed a way to have my things organized in the file drawer and have them stay put when I (or a coworker) rolled the unit to a different spot in the office. The variety of sizes of compartments fits the bill perfectly. Ruler, pens, note pads, even a bottle of tylenol, all stay where I put them and stay organized. It took me a while reading the dimentions of different trays to find the one perfect for me (needed a deep tray), so make sure you measure the space you are going to put this... it is deeper than most.