I was looking at what new training devices people are selling nowadays and it seems like the new thing is those "Ultrasonic" trainers. They are devices which sends high frequency sound waves which only dogs can hear. I don't know much about the subject, but I'm left wondering if this is really a "Humane" device. If it is supposed to stop a dog from attacking you, then it must really be blasting them with ultrasonic waves. I'm just concerned about how they are marketing this as a "Humane, safe and easy" training device to train your dog. People are going to buy this thing and think that it doesn't hurt the dog. I'd like to see how a dog reacts to this thing, I'll try to look for a video.