Thanks Donald. Knowing what to look for helped ... and google knew where to look. The best reference was here ... http://photonotes.org/articles/eos-manual-lenses/ BTW, the item is an Canon Lens Converter FD-EOS and google did fine with just FD-EOS I found out just how much trouble I might have and that none of my FD lenses could work with an EOS body. In summary, I didn't spend additional money and didn't buy additional trouble.