This internally Threaded Titanium Industrial Scaffold Bar in 1.6mm gauge has a middle section that is 2mm in diameter. There is a threaded hole halfway along that accepts attachments for internal thread in 1.2mm (same size as attachments for dermal anchors). This bar has the Daisy top in this hole. The bar is only available in 36mm length which is the most popular size for scaffold bars. While the bar can be autoclaved, the daisy attachment should not be autoclaved.