Custom html after each menu item

Hi guys

I am using the Reverie theme .

In my main primary menu I want to add a custom piece of html (a slash basically, which is being styled up slightly)

I have tried adding this under wp_nav_menu as
'after' => '<div class="menuSlash">/</div>', but this adds it to every item, including the dropdowns.

Is there a way I can add this to only the top level menu items?

Here is the full menu code:

<nav id="primaryNavigation" role="navigation">
					<?php
					    wp_nav_menu( array(
						'theme_location' => 'primary_navigation',
						'container' =>false,
						'menu_class' => '',
						'echo' => true,
						'before' => '',
						'after' => '<div class="menuSlash">/</div>',
						'link_before' => '',
						'link_after' => '',
						'depth' => 0,
						'items_wrap' => '<ul class="nav-bar">%3$s',
						'walker' => new reverie_walker())
					); ?>
				</nav>

Thanks,

Ian