A cordage for threading through an opening. An elastic cord is provided with an elongated shank component and at least one outwardly expandable component. When the cord is under tension, the expandable component shrinks to a diameter which is sufficient to enable its movement through an opening, such...http://www.google.es/patents/US6513210?utm_source=gb-gplus-sharePatente US6513210 - Draw-tight elastic cordage
