They came in a wrinkle finish and a glossy finish. The glossy ones are newer, but inside they are similar. There is a single drive belt inside. Also, these were not made with ball bearings. The bearings need to be lubricated with each use. Consequently they may be frozen up from the oil getting hard. I got mine cheap because it was frozen up from gummed oil. After some cleaning it has worked fine for 8 years.
I have been using Singer® sewing machine oil with mine.