Almost mint condition Zeiss Biogon 21 4.5 for Contax n Nikon rangefinder like IIa , S3. Best 21 as no distortion . Len only with 40.5 mm filter . Got Leica 21 4 that’s why sell it . Just little bit dust . Price firmed
Photo w Zeiss Contax IIa , Ilford XD2 400.
https://filmphotograph.com/carl-zeiss-contax-biogon-21mm-f45-1956-237