This "in front of the lens" shutter looks like it was made in the 1950s. The outside measures 108 mm. The inside opening is 48 mm. The instant and bulb settings work perfectly. The "O" setting opens only halfway. I do not know if this is the way it should be. The synch posts are Graflex. I do not have any rings that will attach the shutter to the front of a lens. Included is a well working Japanese cable release.
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