Packabell requires you to pack the five pieces in the bell so that it can be hung upside down with the clapper straight down without anything coming out.
In the
...Plus center is a real moving clapper, not that much to sound the bell, but to make enough space for each piece to be inserted by moving it in the right directions. That being said, as the bell fills up the clapper's moves become quite restricted and so does the possibility of inserting new pieces.
