<div class="container">
  <a href="#" class="button">Es</a>
  <a href="#" class="button"><i class="fa fa-dribbble"></i></a>
</div>

@import url('//maxcdn.bootstrapcdn.com/font-awesome/4.3.0/css/font-awesome.min.css');


.container {
  position: absolute;
  top: 45%;
  -webkit-transform: translateY(-50%);
  -ms-transform: translateY(-50%);
  transform: translateY(-50%);
  width: 100%;
  text-align: center;
}

/** Button Code **/

.button {
  width: 72px;
  height: 72px;
  line-height: 72px;
  display: block;
  position: relative;
  -moz-border-radius: 50%;
  -webkit-border-radius: 50%;
  border-radius: 50%;
  border: 2px solid #444;
  text-align: center;
  display: inline-block;
  vertical-align: middle;
  position: relative;
  z-index: 10;
  color: #333;
}

.button:hover {
  color: #fff;
}

.button:after {
    position: absolute !important;
  content: "";
  width: 56px;
  height: 56px;
  display: block;
  position: relative;
  -moz-border-radius: 50%;
  -webkit-border-radius: 50%;
  border-radius: 50%;
  right: 8px;
  top: 8px;
  background-color: #333;
  visibility: hidden;
  filter: progid:DXImageTransform.Microsoft.Alpha(Opacity=0);
  opacity: 0;
  -moz-transition: all 0.4s ease;
  -o-transition: all 0.4s ease;
  -webkit-transition: all 0.4s ease;
  transition: all 0.4s ease;
  opacity: 1\9;
  visibility: visible\9;
  display: none\9;
  -moz-transform: scale(0.5, 0.5);
  -ms-transform: scale(0.5, 0.5);
  -webkit-transform: scale(0.5, 0.5);
  transform: scale(0.5, 0.5);
  z-index: -1;
  -moz-transition: all 0.2s ease;
  -o-transition: all 0.2s ease;
  -webkit-transition: all 0.2s ease;
  transition: all 0.2s ease;
}

.button:hover:after {
  visibility: visible;
  filter: progid:DXImageTransform.Microsoft.Alpha(enabled=false);
  opacity: 1;
  display: block\9;
  -moz-transform: scale(1, 1);
  -ms-transform: scale(1, 1);
  -webkit-transform: scale(1, 1);
  transform: scale(1, 1);
}