Thanks Fotch. My guess was not far off. I have been using the Nikor with the hinged clamp for many years, it's a great reel. I look for them at whatever camera show/flea market that comes up. I have only seen one once, so now I have a pair. The other Nikor with the thin strip of metal doesn't seem to clamp in any way. Maybe it's bent. The Kindermann might need more practice. Thanks again.