The stopper has grommets around each cylinder holes, the bead type doesn't.
The stopper is said to seal compression/cylinder pressure better.
If you're not going 25+psi, the bead-type will be more than up to the task.
The stopper has thinner, more numerous layers of metal sheets than the
bead-type; and, you'll notice a *raised* 'stopper' around each cyl hole. The
bead-type has thicker metal layers, & an *indented* bead around each cyl
hole. Sealing of the bead-type is good, but the stopper supposedly enjoys
better sealing & greater longevity. When looking at them side-by-side, I
must admit, the differences are subtle...but the stoppers' price tag surely