There are two demonstrations in this video. The first is quite simple in that it shows that different length pendulums have different periods. It says nothing about angles, bob sizes and masses so your students might like to go off and test these. The starting angle makes a very slight difference when the approximation sin theta = theta no longer holds and therefore becomes significant.

I use the second demonstration to test the student’s grasp of the conservation of energy. You can stop the video before the explanation and get the students to explain what is going on but I think it would be more fun for the students to try and work out what are the conditions needed to make the weight wrap around the stick and then explain the circumstances under which that can happen.