Per reading this thread, I did order it for my daughter's dog who is an avid barker. I am very very impressed and relieved. We also use it occassionally and it has been Wonderful!! It's really Amazing that they stop barking immediately. I worried at first that it would make him nervous and scared, but he really seems more calm after the reinforcement. I say "no barking" and praise afterwards. Of course he is allowed barking @times. So glad I ordered after reading the recommendations! Thanks everyone!!