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Bootstrap class: .progress-bar-animated

<div class="progress">
  <div class="progress-bar progress-bar-striped progress-bar-animated" role="progressbar" aria-valuenow="75" aria-valuemin="0" aria-valuemax="100" style="width: 75%"></div>
</div>

Preview

Sass source

/* _progress.scss:32 */
.progress-bar-animated {
  animation: progress-bar-stripes $progress-bar-animation-timing;
}

Uses variables

/* _progress.scss:32 */
$progress-bar-animation-timing