Thomas' speculum signed Tiemann on the lever of the retractor. This was a variation on a theme of Simm's speculum but it has a retractor instead of a superior blade which largely serves the same purpose, although the retractor can be adjusted in length. The opening of the instrument is also limited by an adjustable screw. The handle s made from crosshatched ebony in an octagonal configuration. A similar instrument can be seen on page 445 of Tiemann's American Armamentarium Chirurgicum