This is a 5-display binary counter board. My intended use for it is to write a repetitive job on the face of it, and switch it back and forth as the job completes and resets (In this case, a list of mechanical jobs for my work, e.g. Oil Filter Tight, Sump Plug Tight, Tyre Pressures, Air Filter, A/C Filter. I'll have several of these boards clipped together, and all the possible jobs written out on them). 

This is designed with compatability in mind, so that you can clip several of them in a row if you need more switches. 

To assemble, print the pieces, slide the coloured beads onto the end of the sliders, slot the sliders into the base piece, and clip on the lid (the one with the holes). If you are stacking multiple together, use the clip in the holes on the corners. 

I printed mine at 200% scale, and it works really well. 100% scale also works reasonably, but I thought it was a bit flimsy.