We ordered this collar for our Cavalier King Charles Spaniel. He is a great dog, very gentle and obedient, but at age 2 has started develop a some pretty annoying barking habits. These range from the harmless but annoying, such as seeing a squirrel out the window, barking like crazy at it and then tearing down the stairs to his basement doggy door; to the embarassing such as going absolutely beserk at the mail carrier and anyone else who happens by our house walking a dog. When he goes into this "beserk" stage, he won't listen and can't be stopped from barking/growling until the "intruder" in his space is gone.
We have tried a couple of different products, namely the PetSafe Outdoor Ultrasonic Bark Deterrent (the one shaped like a birdhouse) for outdoors, and PetSafe PBC-1000 Ultrasonic Indoor Bark Control for indoors. The Outdoor unit worked reasonably well, but our dog figured out pretty quickly that if he got far enough back from it (it was placed near the property line to deter barking at the sidewalk), he could still do his thing (including harassing the mail carrier when they got to the front porch.) The Indoor unit seemed to work for about a week, and then lost its effect (I even put brand new batteries in it, but it just seems the noise it emits doesn't bother him that much.)
After reading reviews for virtually every "no bark" collar on Amazon and other sites, we selected the Dogstra No Bark YS300. Unlike the ultrasonic bark deterrents we had been using before, which rely on an unpleasant noise to stop barking, this collar detects the bark and then delivers a "shock" to the dog. I should add that our dog is trained on and completely comfortable with an electric fence, so to some degree he gets the joke of what it means to get a shock. We have been using this collar for 2 weeks, and so far it works like a charm. The first day that the mail arrived, our dog began his usual barking, and immediately received a corrective shock. He let out a little yelp (exactly what he does when shocked by electric collar for invisible fence), and not only did he stop barking, but he settled down, and never went into his "beserk" mode. When he is in his "beserk" mode at the mail carrier, he often shreds the mail. Not this time. Apparently by stopping the barking, it stopped the whole destructive mode.
The dog very quickly figured out that bark = shock, and I think he has only received one or two shocks subsequently. He has also figured out that a low growl does not trigger the shock, nor does a very quiet "woof" that is almost more like a grunt. So he can still alert us if he believes something is not right (like a squirrel has entered his yard.) I should add that the collar has 7 levels of shock severity, and we have it set on the mildest one.
The last thing I will adress is the battery. The Dogstra YS300 uses a rechargeable lithium battery. So far it seems to need charging every 4 days or so. This is not a big deal, we simply take it off of him at night and charge it as you would a cell phone, an i-touch, etc. This may sound like a lot of charing, but we have been thru so many battery ordeals with his electric fence collar and those batteries are so expensive, that I actually like this method better.