When building drive, it is often done through back tying a dog to create frustration, which elevates drive.
We never use a normal leash or long line for this type of work because each time your dog hit the end of the line, this "shock loads" the line and can cause the snap or ring to explode or the line to break.
Our Back Ties and Bungee Cords are designed to take an incredible amount of shock loading and will not break.