I'll keep poking around to see if I can find out what it is for curiosity sake. Both Dansprint and Speedstroke (the two top ergs) use them, I assume to make rope replacement easier. I'll probably just tie some knots and be done with it, but figured if I could find a couple for a a dollar, I'd try them. I assume they must work well since I have seen these machines used at very high speeds, pulling hard.

thanks,
eric

: I don't see why a twist or swivel joint would be necessary, as there is not
: enough twisting motion involved that the rope and bungee couldn't easily
: absorb it. You can buy plastic clip hooks for bungee ends at marine
: suppliers like West Marine. Tie or splice a loop in the rope, hook it to
: the bungee and you're done.