I received my bark repeller today and holy cow this thing works!

Bailey only barks at my bf's place when he is around my bf's 2 dogs and he barks like crazy in the car. I used it once at my bf's and all the dogs stopped barking immediately, when I was leaving to go home, I put Bailey in his car seat and right away he started barking, so I used the repeller before I got in the car and drove off and Bailey did not bark the whole way home!, I was totally amazed and kept telling him what a good boy he was!! I just hope it doesn't hurt their little ears to much, I'm keeping my fingers crossed that it will only have to be used occasionally!