Josef Nickl was one of the chief R&D designers at Mauser after the Federle brothers, and one of his pet projects was a rotating barrel military pistol developed from the Steyr-Hahn M1912 pistol. He built a number of prototypes of it while at Mauser, but the company never put it into production because of a combination of patent concerns and wartime contracts for other weapons. Eventually Nickl was able to arrange a contract for it to be produced at Brno, where it would become the CZ24 and then CZ27 pistol. This particular one is a larger example, in 9x19mm.