I saw one of these at a gun show once. The barrels on the one I saw rotated. Each barrel had a nipple, of course, but there was only one lock. It looked to be .40 caliber or less. I did not see any legible markings, or the maker's name. It was priced at $400, and was still there when I left. This was mybe five years ago, in Cobb County, Ga.