Ashley's stopper knot, also known as the oysterman's stopper, is a knot developed by Clifford W. Ashley around 1910. It makes a well-balanced trefoil-faced stopper at the end of the rope, giving greater resistance to pulling through an opening than other common stoppers. Essentially, the knot is a common overhand noose, but with the end of the rope passing through the noose eye, which closes upon it. It may be multiplied to form a larger knot with more than three bights appearing around the knot. It is the result of implementing a double wall knot in one strand. — The Ashley Book of Knots