The Extreme Bungee Line is an excellent tool for building drive and power in your dog. It is made with two bungee lines for the heavy hitters, and our lines are superior to any other on the market. We use a special manufacturing process that takes high quality shock cord and inserts it inside tubular webbing. The webbing is then bunched up to allow the line to stretch, and is knotted off with shock cord. The 7' line stretches to approximately 11', giving you and your dog plenty of room to work.