The figure-eight knot is a type of stopper knot.
It is very important in both sailing and rock climbing as a method of stopping ropes from running out of
retaining devices. Like the overhand knot, which will jam under strain, often requiring the rope to be cut,
the figure of eight will also jam, but is usually more easily undone than the overhand knot.
Figure-eight knot, Figure-of-eight knot, Savoy knot, Flemish knot, Double stopper.