max

max - Specifies a maximum pane size. It can be given in pixels or as percentage value.

<div id="container" style="height: 300px" >
   <div>Pane1</div>
   <div>Pane2</div>
</div>

<script type="text/javascript">

     $(function () {
        $("#container").shieldSplitter({
           orientation: 'vertical',
           panes: [
              { size: "100px", max: "150px" }
           ]
        });
     });

</script>