This is the Olympus C-210 1.9x Tele-converter. I has a 49mm camera end threads and no filter end threads. It can use on a lot of Olympus cameras, using an adapter ring. It does have a lot vignetting Even at full zoom.
To see this lens in action here is a link.
http://www.pixelbrat.com/teleconverters.html

By Bill Huber