This, is the Kolibri pistol.
Made in 1914 by an Austrian watchmaker named Franz Pfannl, it holds the record for being the smallest gun ever made.
It was called Kolibri due to it’s small size (Kolibri being the German word for “Hummingbird”, a type of bird known for being very small), and took 2MM bullets. It was advertised as being a ladies self-defence weapon, as it could be easily stored in a handbag or the pocket of a woman’s coat.
However, the gun proved to be a terrible self-defence weapon, as it had small range and horrible accuracy, combined with the fact that the bullets lacked any stopping power (There we reports of the bullets harmlessly bouncing off a muggers wool coat when he was shot at, and even sometimes bouncing off bare skin!). Due to these factors, the gun was considered not to be a worthy buy, and was discontinued in 1938.
It is now a collectors item, as it’s reported that only 1000 of these guns where ever made.
The gun gained more mainstream/wide spread attention after it was featured in the EA’s 2016 game Battlefield 1, as one of the last unlockable handguns in the game’s multiplayer mode, and for being considered to be one of the worst guns in the game (Although the weapons inclusion was most likely added as a joke).