OK, so someone here must know:

You can buy what looks like a single link of chain,
but one side has a long nut-like thing on it.  When
you unscrew the nut, it opens up a gap (so now you
have a 'C') enabling you to slide chain through that
gap.  Then you tighten the nut thing again and you've
made a solid link again.

What's that single-link-with-a-hole-and-nut thing
called?

thanks!

tabe johnson/87 westy