A Pen by jupegarnica.

<div class="wrap">

  <input type="checkbox" id="s1" />

  <label class="slider-v1" for="s1"></label>

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  <input type="checkbox" id="s2" checked="" />

  <label class="slider-v1" for="s2"></label>

</div><!--/wrap-->

<div class="wrap">

  <input type="checkbox" id="s3" />

  <label class="slider-v2" for="s3"></label>

  <input type="checkbox" id="s4" checked="" />

  <label class="slider-v2" for="s4"></label>

</div><!--/wrap-->

<div class="wrap">

  <input type="checkbox" id="s5" />

  <label class="slider-v3" for="s5"></label>

  <input type="checkbox" id="s6" checked="" />

  <label class="slider-v3" for="s6"></label>

</div><!--/wrap-->