I wish I was able to post a picture, but I don't currently have access to the needed equipment. The reaction chamber is very large, eyeballing it at a touch over a foot tall, and maybe 7 inches wide. The chamber narrows sharply at the top, and empties directly into the cup, the only uplift tube being containted within the cup itself. There is no true union fitting like the newer ones. The skimmer is powered by a Sedra 3500. Does this sound like the G series?
Thanks,
Justin Collins