Dog Silencer Max stops 3 noisy neighbor dogs

Our neighbors have 3 dogs that bark at the drop of a pin and don't stop for a long time. I bought the Bark Control Max and installed batteries. I also bought the amplification cone. I was placing it near the fence when they heard me and ran over barking aggressively. I turned it on and they immediately stopped barking, let out whimpers and ran back to their house. They stayed there looking in my direction with their ears down looking worried. There has been a huge improvement in our peace and quiet, while not having to confront our neighbors. In fact, I am buying another one to cover the other half of there yard that is adjacent to ours, as it is about 175' of fence line.