SUPER cool, loved it, but I think it lacks a full explain with tech details of the high voltage driven bell, how exactly does it work ? what is connected to positive and negative ? if you remove the glass, how loud is the sound ? what is the voltage now ? and how high was the voltage back then when it was made, it is easy to find out what is in side and how many stacked cells, simply by using xray, it is not that fancy anymore, many use it to check electronics with.