cls

An optional CSS class to set for the Droppable element on initialization.

<div id="div2" style="width:100px; height:100px; border:1px solid black;">
    Drop items here...
</div>

<script type="text/javascript">
    jQuery(function ($) {
        $("#div2").shieldDroppable({
            cls: "custom-droppable"
        });
    });
</script>