by Phugoid » Mon Nov 22, 2010 5:48 pm
A single loop, ie one strand made into a loop.
For these it is simple, hold one end and twist the rubber along its length, the bring the two ends together and tie the knot. If it's not enough undo the knot and twist some more....
This is how I do it anyhow....
As for the tool, I can't think it's original, I must have seen it somewhere in the dim and distant past....