The depth is the same on each, with a variety of pocket sizes and widths as diagrammed below.
Our original design—13" by 8.75", with four distinct pockets to give you space for a variety of things. It nests perfectly in the right hand side of the desk shelf.
Holds: Pens and pencils + thumb tacks + your wallet + chapstick + AirPods + a few thumb drives.
The medium is (as you might expect) our middle size. In many instances, it can be just right, just like the fairy tales say. It fits on any of our desk shelves. It's almost a perfect square, 8.6" x 8.75", with two pockets to organize your things.
Holds: A few pens + your wallet OR your three favorite highlighters + your AirPods + chapstick.
The small: a simplified storage solution. Our narrowest tray, it has a single cork pocket, for a minimal tray that cleans things up nicely.
Holds: A handful of colored pencils OR your AirPods + a USB thumb drive OR $3 in loose change.