.img-comp-container {
  position: relative;
  margin: 1rem;
}

.img-comp-img {
  position: absolute;
  width: 100%;
  height: auto;
  overflow:hidden;
}

.img-comp-img img {
  display:block;
  vertical-align:middle;
  max-width: none;
}

.img-comp-slider {
  position: absolute;
  z-index:9;
  cursor: ew-resize;
  /*set the appearance of the slider:*/
  width: 40px;
  height: 40px;
  background-color: #2196F3;
  opacity: 0.7;
  border-radius: 50%;
}

div#heightImgLeft >div {
    top: 50%!important;
    transform: translate(0%, -50%);
}