This is meant to be used on Ikea NOJIG 20x25cm organizers which have the tie bar clipped on and the smaller organizers inside. It's a two-part design, which slides on from each end. The parts are different sizes so that they align with the compartments inside Each part is in its own STL file, and they are meant to be printed upright, without supports. If you have issues with bed adhesion, I suggest you try using a brim or print the third file with both parts fused together with tabs you can cut off after.

Thanks to @credodenny on Thingiverse for the idea.

I might upload a variation which better fits the box without the tie bar and the smaller boxes inside