Can you identify the camera that uses this yellow Voigtlander filter?

I found this - don't know anything about it or where it came from. Can you guess which camera (s) it was intended for? Date?

Free to whomever owns the proper camera for it and will use it (USA only- just send $2 cash for postage- no Paypal!)

Keith Ostertag

It may well fit a 203mm f7.7 Ektar, I have two similar sized Rodenstock filters (a yellow and 1.5X Tele) that fit my Ektar. Most likely sold originally for a pre-WWII Skopar or Heliar on a 9x12 (cm) Voigtlander Avus or similar.

Pre WWII filters and lens hoods were mainly push on not all lenses had a filter thread.

Ian