What's in the box?

I saw these at the ASE Conference and whilst chatting to the lovely people I was with, and the person manning the stand, I could see how they could be used in a "How Science Works" lesson.  I could also see that they could be home-made so I asked the science technicians at work what they could do. This is the result:

As with the set you can buy, I have no idea what is inside the boxes - only one of the technicians knows, and he isn't saying!

This video has given me some idea of how to use the boxes for more than a starter in a lesson.  A colleague also suggested that the pupils could design further experiments to provide more evidence, for example, finding another one of the suggested object and weighing it to compare.  I plan to at least give them to year 13 to have a play with at the start of a lesson, and they'll be great for that class where only half ever appear on time.  I definitely want to have a go at a whole lesson, maybe with year 7, this week.