Mine need to get into the mode of walking correctly *one at a time* before I take them together. If I haven't taken them for walks for a while, we have to do refresher courses. Once they do good that way, I will take them together. One heeling and the other out in front on the expandible leash. This is the only system that works well for walking the two of them at the same time. I tried the coupler but realized that instead of two thirty pound dogs, I know had a team that equalled 60 pounds, more than I could make an impact on with a correction.