This is the renowned 11817 Leica summicron 50mm f/2 lens for M mount rangefinder camera. It is version 3 optical design. 

The lens is in bargain condition. It was CLA'd by Youxin Ye in October, 2016. The optics are clean and clear. There are two coating rubbing-off under the first element. These coating rubbing-off are not likely to affect the image quality since they are located at the very edge of the front element.  Figure 2 shows these two imperfections. Other than these, all are perfect. Aperture clicks as it should without any oil on blades. The barrel shows little sign of use. It has E39 filter thread accepting 39mm filter. It can be adapted on M-mount camera, like the classic M3, M4, M2, modern M6, M7, MP, or digital M8, M9, M240, monochrom (it is usable, but it need to be 6-bit coded for the camera to recognize the lens and thus write EXIF data on the image file). With appropriate adapter, it can be mounted on Sony NEX cameras, Fuji X-mount cameras or micro 4/3 (m43) cameras.

Made in Germany, come with original front and rear caps, the  plastic case and the box with matching serial number.

I will ship insured to confirmed US, Canada or Australia address only. International buyer is responsible to any customs. Thank you!