Cubes are furniture for a bag. A good set has a published size (or a named set), a zipper you can name, and a page that still exists.
We log Peak Design’s modular cubes, Eagle Creek’s Pack-It Isolate line, Cotopaxi Cubo, and Away’s cube sets because those pages list materials or dimensions we can cite. We do not invent compression ratios.
If a cube page only says “small / medium / large” with no liters, we say so.