This is a late model (1951) Leitz 5cm f2 Summitar lens for Leica Thread Mount in good cosmetic condition, but with a few notable issues: there is some separation at the edge of the front element group, which does not appear to affect imaging- test images look like other Summitars we've tried- but will be apparent to visual inspection with a bright light. Focusing is smooth, diaphragm works well, though it does have some evident surface spots. Imaging is good, though this is a Summitar, not a Summicron, so you can expect some softness as a general rule.