These Little Atom 2mm pinfire cap gun pistol cufflinks were imported from Japan by G & S Mfg. Co., of Nashville, Tennessee beginning in 1950. They sold them wholesale to small shops across the country.
An original cased set is very rare. This set comes with a set of two cufflinks, the cartridge extractor and an original tube of 2mm pinfire cartridges. They are also the version with the fully bored-through barrel that can fire blanks or ball rounds.
The following video shows the functionality of these pistols:
For more information please read the full article on these: 2mm Pinfire Guns and Cartridges