One of the wonders of the photographic world before World War II was the 180/2.8 Sonnar. Often referred to as the Olympia Sonnar as it was introduced for the 1936 Winter Olympic games. There was nothing that anyone offered that even came close to rivaling it initially, it brought back memories of the Ermanox high speed cameras of the mid 1920's.
While by today's standards it's nothing much, we can buy 400/2.8 lenses now, it was never matched by Leitz in rangefinder mount, and was available for their reflex cameras in 1968. Nippon Kogaku would match it with their 180/2.5 in late 1953. Keep in mind that this lens was built without lens coating.
First introduced in direct rangefinder coupled mount, and in chrome finish, it was offered in 1938 in short mount for the early Contax reflex housing, the Flektaskop. Many of the earlier lenses were converted to Flektaskop mount, or other mounts. A few were built in 1940 with aluminum barrels.
After the war, limited production was resumed at Jena, mostly in mounts other than Contax. One was finished in ivory enamel as a sample for use with an ivory painted Jena Contax, but serial production was never started. Most postwar lenses were finished in black, and the lens continued to be available for years in many other mounts including Exakta, 42mm thread and Praktisix/Pentacon Six mounts.
In 1951 the Flektaskop was replaced by the Flektometer, which contained a prism finder, producing an upright and right reading, bright image. Apparently only 200 Flektometer housings were produced.