For School, College or Hobbyist alike.
Ever keeping Arduino pro mini or other similer stuck in breadboard where you running out of pin to insert. This one I made to use 2 breadboard separated to leave last pin to plug in pro mini, now I have more room to inserted.
Other what I can use like for example -- tray be used, collecting screws from your case, useful to stop mixed up screws or screw rolling away.
I have made a near matching this BB Tray to the LCD Lab I made earlier. http://www.thingiverse.com/thing:1477853
Uses 4x 170 sockets breadboard