activateDuration

activateDuration - Specifies tab activation duration. Its default value is 160ms.

<div id="tabs">
    <ul>
        <li>One</li>
        <li>Two</li>
    </ul>
    <div>Tab Pane 1</div> 
    <div>Tab Pane 2</div>
</div>

<script type="text/javascript">
    $(function () {
        $("#tabs").shieldTabs({
            animation: {
                enabled: true,
                activateDuration: 250
            }
        });
    });
</script>