Ok, you're talking about a centerbox, which is not the same as a listing page. That will be a different file to edit.
In /includes/modules/featured_products.php, this section (around line 53) creates the content for each product. You can add spans or add classes to link elements as required.```php
while (!$featured_products->EOF) {
$products_price = zen_get_products_display_price($featured_products->fields['products_id']);
$list_box_contents[$row][$col] = array('params' =>'class="centerBoxContentsFeatured centeredContent back"' . ' ' . 'style="width:' . $col_width . '%;"',
'text' => (($featured_products->fields['products_image'] == '' and PRODUCTS_IMAGE_NO_IMAGE_STATUS == 0) ? '' : '<a href="' . zen_href_link(zen_get_info_page($featured_products->fields['products_id']), 'products_id=' . $featured_products->fields['products_id']) . '">' . zen_image(DIR_WS_IMAGES . $featured_products->fields['products_image'], $featured_products->fields['products_name'], IMAGE_FEATURED_PRODUCTS_LISTING_WIDTH, IMAGE_FEATURED_PRODUCTS_LISTING_HEIGHT) . '</a><br />') . '<a href="' . zen_href_link(zen_get_info_page($featured_products->fields['products_id']), 'products_id=' . $featured_products->fields['products_id']) . '">' . $featured_products->fields['products_name'] . '</a><br />' . $products_price);
$col ++;