Super wide-angle lens, Super-Angulon 21mm f3.4. Serial number in the 2,780,000 range, manufactured in 1976. Finished in black chrome, manufactured by Schneider. Leitz product code is 11103.
The filter size is E48, or it can be used with a Series VII filter when combined with the 12501 hood. The rangefinder coupling works up to a minimum distance of 1 meter, but visually focusing is possible down to 0.4 meters, which is a welcome feature in the era of live view dominance.
The rear element protrudes significantly, so when using the lens with a camera via an adapter, ensure that the rear of the lens does not contact the camera's internal parts. Also, since metering will not function correctly, please use manual exposure settings.
On digital Leica M cameras other than the M11, you may experience vignetting around the edges, so shooting in monochrome is recommended to take advantage of the unique dynamic shadows and compositions possible with this ultra-wide-angle lens.
Included are the 12501 hood, genuine front and rear caps, and a non-original hood cap.

There is minor black paint wear due to hood attachment and detachment, but overall, the lens maintains a very clean appearance. The included hood shows some signs of use, making it perfectly suited for practical use with a 93% good condition rating.
A full overhaul was completed in April 2024, including focus adjustment. The aperture and helicoid are at the appropriate torque, ensuring smooth shooting. The rangefinder coupling is also precise.
There are very slight signs of coating wear on the glass, but these are only noticeable when examined under strong LED light and should not impact your photography. The results from actual shooting tests were also good.