or only the required viewport -->
      <div class="clearfix visible-xs-block"></div>

      <div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>
      <div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>
    </div>
  </div>
{% highlight html %}
<div class="row">
  <div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>
  <div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>

  <!-- Add the extra clearfix for only the required viewport -->
  <div class="clearfix visible-xs-block"></div>

  <div 