We have a Boxer Ridgeback and a Bardino-Podenko mix dog. I have both. On a leather leash with this coupling and it is Super The 2 lines have yet extremely stressed me and so it is very relaxing to go with the two walkies. You quickly get used to it and now run nicely next to each other instead of time re. li times. The two have a few centimeters difference in size but it does in this coupling from nothing.