Leica Leitz New York "A" 85B? Filter for Summitar 50mm f/2
This is a color correcting filter for the Leica Summitar 50mm f/2 lens. It seems like an 85 or an 85B which would allow you to shoot tungsten balanced film in the daylight without losing out on color quality. It is a small thread size that screws into the front of the Summitar 50mm.
The glass of this filter is clean and scratch-free. The front coating has very slightly degraded giving it a mottled appearance in reflection but this is not visible at all when sighting through the lens.