I use the same as momof4 and I love it. The backup goes on their back and then does up around their waist so they can't slip out of it and the leash attaches to my wrist. When you are pushing a stroller and have 1 or 2 walkers it is just much more safe IMO.

However, I do understand why some people do not like them. It does sorta give the child a sense of false security and sometimes it makes the child not want to hold your hand when not using the leash because they are used to having more freedom. However, I still use them!!