Hey Jim,
It’s the 20 inch production model. It was built to be used in an industrial setting. I absolutely love it. The mechanical shop where I work has a 20 inch Rikon drill press. After I finished putting it together, I realized that it looked very familiar, so I took some notes, and the next time I got to the main shop, I took a close look at the Rikon at work. The only real difference I can find is the Rikon at work has a variable speed drive. I have to change belt positions on mine. Aside from that, they are identical down to the casting marks. Just a paint job, and the Rikon has fancier handles on the quill levers.
It has excelled at everything I have asked it to do so far, including using it as a spindle sander, a mortising machine and a vertical lathe. It may well be the best machine I own. :-)