Description
Serial #2387577
Made in Wetzlar, Germany in 1970 2nd version example, desirable German made version
This is the version before the focusing tab and the M marking on the name ring. 

Black finish
Dual scale yellow/white feet/meter focusing scale with focusing tab
Classic compact 50mm lens

A desirable version as it helps to have without the infinity focusing lock, still made in Germany ( as the later version was made in Canada ) and nice to still have the older style script and marking on the name ring as SUMMICRON instead of the later Summicron-M 
NICE!

Details
6 elements 4 groups
Aperture range: f2 - f16
47° angle of view
E39 filter mount
Cat No. 11817

Includes
Front/rear lens caps
Leica 12585 lens shade
Bubble case
Matching serial number box

Cosmetics 9/10
No dings, dents or major marks
Lens barrel is very pretty

Mechanics 9.5+/10
Focusing is smooth
Aperture clicks are crisp

Optics 8*/10
No fog, fungus, separation or scratches
There is a line inside the glass. It is faint and only seen with an LED light and it is not on the surface. I can't get to it as it is on the inside and I am sure it is cleanable. Insignificant and almost sure there is a solution but it is there*