We'll edit this file:

/components/com_virtuemart/views/productdetails/tmpl/default.php

Note that if you are using a Virtuemart template, you might need to edit the file that is in your template directory instead.

Place this code somewhere at the top (or bottom) of the file:

function list_product_type($pid) {
    $db = JFactory::getDBO();
 
    $html = "";
    $q  = "SELECT * FROM #__fastseller_product_product_type_xref ";
    $q .= "LEFT JOIN #__fastseller_product_type USING (product_type_id) ";
    $q .= "WHERE product_id='$pid' AND product_type_publish='Y' ";
    $q .= "ORDER BY product_type_list_order";
     
    $db->setQuery($q);
    $pts = $db->loadObjectList();
     
    $q  = "SELECT * FROM #__fastseller_product_type_parameter ";
    $q .= "WHERE product_type_id=";
    foreach ($pts as $pt) {
        $html .= "<br />\n<table width=\"100%\" cellspacing=\"0\" cellpadding=\"0\" border=\"0\">\n";
        $html .= "<tr><td colspan=\"2\"><strong>Info: ".$pt->product_type_name."</strong></td></tr>\n";
         
        // SELECT parameter value of product
        $q2  = "SELECT * FROM #__fastseller_product_type_".$pt->product_type_id;
        $q2 .= " WHERE product_id='$pid'";
        $db->setQuery($q2);
         
        $info = $db->loadAssoc();
         
         
        $db->setQuery($q . $pt->product_type_id ." ORDER BY parameter_list_order");
        $params = $db->loadObjectList();
         
        foreach ($params as $param) {
            $html .= "<tr class=\"\" height=\"18\">\n";
            $html .= "<td width=\"30%\">".$param->parameter_label;
             
            $html .= "</td>\n<td>";
            $html .= $info[$param->parameter_name]." ".$param->parameter_unit."</td></tr>\n";
         
        }
        $html .= "</table>\n";
    }
     
    echo $html;
}

And now place this function call wherever you want to display assigned Product Type information on the page:

// now call function
$pid = JRequest::getVar('virtuemart_product_id', null);
list_product_type($pid);