This is a 4x4 divider for the Sortimo 100mm^2 blue bin to allow for 16 small parts compartments.
The fit with the Sortimo bin is pretty tight, but still should slide smoothly in and remove without issue.
You'll want to make sure you don't have any excess material around the edges. A light pass with some sandpaper should do the trick.
After modelling the Sortimo 100x100 bin in Fusion 360, I then made myself a series of inserts for various uses.