This is an uncommon M mount Leitz Elmar 5cm f3.5,released in 1954 alongside the M3.Leica would later produce a redesigned f2.8 version, but this is the original from the first year of production. Just back from a full service, with smooth focusing and good diaphragm action. Very light haze and dust, no fungus or any other artifacting that will affect imaging. Cosmetic condition is very good, with light barrel wear. Includes front and rear caps.