Removable bins for Flambeau cases. Helps to keep small parts from squeezing underneath the stock dividers into adjacent compartments. The drafted parts fit everywhere in my cases but are a little awkward in the corner. There is a corner part that works a bit better there. You can cut the top off or end the print early to make shorter bins that stack in the Flambeau case.
This is the case these were designed for.
These cases have a slightly different geometry than this part (https://www.thingiverse.com/thing:2388554) was made for.