The Saxon IV K were narrow gauge, 0-4-4-0T Günther-Meyer type steam engines built for the Royal Saxon State Railways with a track gauge of 750 mm (2 ft 5+1⁄2 in). A total of 96 were built between 1892 and 1921, making the Saxon IV K the most numerous narrow gauge locomotive in Germany. In 1925 the Deutsche Reichsbahn grouped these engines into their DRG Class 99.51–60.