This is a very functional/useful leash that allows you to 'arm swing' during your walk/run with you dogs.  This 'extra buddy' added a leash to my BUDDY SYSTEM that allows me to easily bring both of my dogs.  It took a few days but the dogs do very well with the system and I love the quick release system to quickly re-position the dogs.  This is one of the best running training tools that I have bought...