Zeiss Ikon 354 IcolorB 2.5x 40.5mm Screw On Filter in Plastic Case NEAR MINT V21

This near-mint condition vintage Zeiss Ikon 354 IcolorB 2.5x 40.5mm blue screw-on filter comes in a Voigtlander plastic case. The filter appears to be unused. The case has scuffing and scratching on its exterior.