This is a very nice Pre-War Zeiss Ikon A42 Distar Close-Up Filter
For Contax/Nikon Rangefinder Cameras lenses with 40.5mm filter threads
(including 5cm f2.0 & 1.5 Sonnar/Tessar, Nikon 50mm f2.0, 135mm, etc..)
Made in Germany
Glass is in very nice condition
You can adjust the snugness of fit with the little tabe on the ring
Comes in it's original matching Carl Zeiss Jena Bakelite Protective Filter Case!
*shown on Contax II Zeiss 5cm f2.0 Tessar lens, which is not included
Actual picture of item listed.