This Sigma APO teleconverter is in mint condition, except for a couple of little scratches on the inner black ring at the back of the unit as shown in the 2nd photo.
Excellent optical performance, excellent build quality. The lens mount has 10 pins.
Please note-the autofocus function is possible only with a certain number of lenses, and NOT all. If you will Google "sigma 2x ex dg apo autofocus teleconverter for Nikon AF compatibility" you will a get a chart, and then you will be able to determine if this unit will autofocus with your lens.
You would use it as manual focus otherwise.
Selling AS-IS, no returns.