<div class="fs-grid">
	<div class="fs-row media_gallery">
		<div class="fs-cell-centered fs-lg-9 fs-xl-8">
			<div class="image_viewer js-viewer">
				<img src="//spacehold.it/1600x900/1.jpg" alt="">
				<img src="//spacehold.it/800x1200/2.jpg" alt="">
        <img src="//spacehold.it/1400x1400/3.jpg" alt="">
        <img src="//spacehold.it/1600x900/4.jpg" alt="">
				<img src="//spacehold.it/800x1200/5.jpg" alt="">
        <img src="//spacehold.it/1400x1400/6.jpg" alt="">
      </div>
    </div>
  </div>
</div>

.image_viewer {
	margin-top: 30px;
	margin-bottom: 30px;
}
.image_viewer.fs-viewer .fs-viewer-wrapper {
  height: 400px;
}

$(document).ready(function() {
  
  $(".js-viewer").on("loaded.viewer", function() {
    console.log("Loaded!");
  }).viewer();
  
});