Cool Rio.
Be careful though as I believe the old ones like that may be classified as AOW by the Waffen ATF.
https://ctfirearmsauction.com/what-is-a-pen-gun-and-is-it-a-legal-firearm-unique-guns-at-auction/“Through the Second World War and the Cold War, the pen guns used by spies are legally classified as an AOW. So, you can’t easily buy models like the Penguin unless you complete NFA paperwork for a tax stamp. But, unlike these spy weapons, the Stinger pen gun is unique, in that it is classified as a legal handgun by the ATF and readily transferable like most guns.”
