The Köf II was a legendary workhorse in hard switching work. Even today these small locomotives are giving faithful service on numerous industrial and plant railroads. The first of these very reliable and sturdy units was placed into service as early as 1934. A total of over 1,600 locomotives were built by 1965. The maximum speed was 30-45 km/h or 19-28 mph, depending on the production series. A 6-cylinder diesel motor produced 128 hp in the most powerful version.