Silence is indeed golden

This is the best product, I have 2 boxers, out of control barking - the first time I used this on the lowest setting, they took notice and within a few days (less than a week), all I had to do was reach for the box to turn it on, and they stopped barking!! Now, all I have to do is say 'no bark' and they do not bark....rarely do I have to turn the unit on!! I cannot say enough good about this product!! Silence is indeed golden.....