From the look in the picture, you'd need one of the brass-looking hexnut-style adapters to go into the clamp.... this has a 1/4" (?) adapter on the end for putting your vert bar, t-bar, whatever else. If you do an ebay search for "bogen super" you'll see one of the units I'm talking about up for auction. I'm not positive this is what you need, or *if* you need one at all, but it looks right.
I'd pay $15 assuming everything is included.... although $20-30 for a brand new in buy-it-now isn't bad either!