I have had one of these rolling around in my tool box for years and was never sure what it was. I thought it was a XXXXXX XXXXX but it did not seem to work for that.

I recently found another one at a shop in Portsmough NH (they have two old Schwinn Tandems with a curved ST on the Stoker position). anyway I was snooping around for old stuff and found one of these hanging from the ceiling in it original pacakge.

you oldtimers like me if you know just say Yes and give the youngins a chance to ponder it.