These are inserts for the 4 in. Stacking Tilt Bin from harbor freight. You can use a thin piece of plastic for the front view panel sourced from just about any kids toy packaging view window.

This insert for the Harbor freight 4in tilt boxes to store more smaller screws or accessories in on box. There is a Chamfer at the bottom to somewhat lock into the bottom of the box so it need to be printed with supports touching the build plate. I can publish one without the chamfers if someone would like.