The Frommer/Femaru 37M was the last in the line of handguns designed by Rudolf Frommer. The 37M was a single-action blowback pistol chambered for .380, although it was also purchased by Germany in .32 ACP caliber (and with the addition of a manual thumb safety). It was adopted by the Hungarian military in 1937, replacing the 29M - which was mechanically basically identical but more expensive to produce. The 29M, in turn, was basically a scaled-up Frommer Lilliput.