I've never liked the idea of these type of collars but now I've been won over. I own a stubborn Pitbull who just did not understand I didn't want her barking every time she got excited (which is often), or barking every time there was a noise out in the street (all the time). I phoned and spoke to one of the wonderful sales staff, who recommended one of their collars, which I purchased. When I received it I set it on automatic, for when you want them to still bark at danger but not nuisance type barking. It has a Pavlov beep which warns them an unpleasant zap is coming if they continue, and literally within hours she had calmed down significantly. Funny thing is, it doesn't seem to be the zap that stops her. She only has to hear the Pavlov beep and she is so distracted looking for where it has come from, that she stops barking. Only a week later and she still isn't nuisance barking even when the collar is off her. I am much less stressed about it and I'm sure my neighbours are too! Thank you Dog Line!!