My kids have accumulated a lot of Lego sets over the years and it has become really hard to find a piece that you're looking for. I needed something that could be quickly used when the kids are in the mood to build.
I think of this like an inexpensive search index for all of our legos.
The trays are sized to fit on a MK3 as and I tried to get the maximum surface area I could to allow for lots of legos to be dumped in at once.
The author marked this model as their own original creation.