This is a container for used safety razor blades that fits in gridfinity bins with thin lip that are 12 units in height.
I've included such a 1x1x12 gridfinity bin, but you can also see a picture of the box in a 1x2x12 gridfinity bin designed using gridfinity generator.

It has a sliding lid at the bottom so you can safely dispose of the used blades once the box is full, but still keep the box.

⚠️ Make sure you dispose of the blades according to the guidance in your region or country, don't simply throw them in the recycling bin where they could be a safety hazard for workers down the line!