Voigtlander 317/41 AR 40.5mm AR UV Filter for Zeiss BIOGON 1:4.5 f=21mm Biotar
Filter thread size for Voigtländer 40.5mm 317/41 AR Focar A f=1m Filter:
40 5mm
Voigtlander Bessamatic PL 4-2m 13-6.5feet