>>11036718They are multi purpose acrylic boxes with a magnetic door.
each shelf has 3 of them and yes the middle component is removable.
https://www.amazon.com/dp/B0C3V2PDSPThey could be deeper, but i bought the boxes before i bought the metal shelf.
they aren't perfect but they keep the dust off my figures and since i have dogs i have to constantly fight the dust and hair they bring