This is a first-year (1938) Leitz 5cm f2 Summitar lens for Leica Thread Mount in good usable condition, with clean glass and smooth focusing- but a fair bit of cosmetic wear, mostly on the collapsible barrel. The focus tab infinity lock (the spring-loaded part) is missing, which is technically a flaw but honestly, it's a usability improvement. Good imaging. A nice vintage lens with the "old" aperture sequence (to f12.5)