silverstripe-framework/admin/templates/Includes/LeftAndMain_SilverStripeNavigator.ss

<div class="cms-navigator">

    <span class="preview-selector field dropdown">
		<select id="cms-preview-mode-dropdown" class="preview-dropdown dropdown nolabel" autocomplete="off" name="Action">
			<option data-icon="icon-split" class="icon-split icon-view first" value="split"><% _t('SilverStripeNavigator.SplitView', 'Split mode') %></option>
			<option data-icon="icon-preview" class="icon-preview icon-view" value="preview"><% _t('SilverStripeNavigator.PreviewView', 'Preview mode') %></option>
			<option data-icon="icon-edit" class="icon-edit icon-view" value="edit"><% _t('SilverStripeNavigator.EditView', 'Edit mode') %></option>
			<option data-icon="icon-window" class="icon-window icon-view last" value="window"><% _t('SilverStripeNavigator.DualWindowView', 'Dual Window') %></option>
		</select>
	</span>
	
    <span class="preview-selector field dropdown">
		<select id="cms-preview-mode-dropdown" class="preview-dropdown dropdown nolabel" autocomplete="off" name="Action">
			<option data-icon="icon-auto" data-description="<% _t('SilverStripeNavigator.Responsive', 'Responsive') %>" class="icon-auto icon-view first" value="split">
				<% _t('SilverStripeNavigator.Auto', 'Auto') %>
			</option>
			<option data-icon="icon-desktop" data-description="1024px <% _t('SilverStripeNavigator.Width', 'width') %>" class="icon-desktop icon-view" value="preview">
				<% _t('SilverStripeNavigator.Desktop', 'Desktop') %>
			</option>
			<option data-icon="icon-tablet" data-description="800px <% _t('SilverStripeNavigator.Width', 'width') %>" class="icon-tablet icon-view" value="edit">
				<% _t('SilverStripeNavigator.Tablet', 'Tablet') %>
			</option>
			<option data-icon="icon-mobile" data-description="400px <% _t('SilverStripeNavigator.Width', 'width') %>" class="icon-mobile icon-view last" value="window">
				<% _t('SilverStripeNavigator.Mobile', 'Mobile') %>
			</option>
		</select>
	</span>


	<div class="cms-preview-states switch-states">
	    <input type="checkbox" name="cms-preview" class="state cms-preview" id="cms-preview-state" checked>
	    <label for="cms-preview-state">
		    <span class="switch-options">
		    	<% loop Items %>	
		    	$Items.count    	
		    	<a href="$Link" class="$FirstLast <% if isActive %> active<% end_if %>">
		    		$Title		
				</a>
				<% end_loop %>
		    </span>
		    <span class="switch"></span>
	    </label>
	</div> 

</div>