Pop beads were made of soft plastic and featured a knob at one end that would fit into the bottom hole of other beads. And, yes, when you pulled the beads apart, they would make a “popping” sound. They came in a large or small size and most often came in pastel colors. Unfortunately, they don’t seem readily available anymore, especially in their original sizes. (If you really want the original pop beads, look for them as “retro jewelry.”) There is a giant size readily available; giant, as in there is no way that these pop beads could cause a choking hazard. These new pop beads still prove to be popular with children, but I, for one, would much prefer the original pop beads of my youth. I loved these pop beads!