Bests & Worsts Reviews from Amazon

I don't like these collars. I put them on in the morning and a hour or so later I may let the dogs outside. Well our problem is barking so I will "vibrate them or shock them" as needed. But nothing happens. The collars are fully charged but it's like they go into sleep mode sometimes. And I need them to vibrate right away to take care of the problem not for me to have to call them in to check their collars.