Inspiron 14z (n411z): Optical Drive Height?

I want to move my optical drive to an external caddy.  External caddies fit standard heights of 9.5mm or 12.7mm according to http://www.newmodeus.com/shop/index.php?main_page=index&cPath=12

Product support just lists the part as "Toshiba Samsung Storage Technology".  How do I work out which caddy I need without disassembling my laptop?

Thanks!