Bests & Worsts Reviews from Amazon

This is most useful inside the home at very close distances, or in a small enclosed yard. It was useful, for example, discouraging my dog from jumping on the couch. But it does not seem to have nearly the claimed range of 900 feet. Outdoors in an open field, it was useless. Also, it is not powerful enough to have any effect on a really excited dog. Indoors, when my Aussie is relatively calm, a setting of about 70 (out of 100) is enough to discourage unwanted behavior. He'll stop what he's doing and shake his head a little. But outdoors off-leash in a field, when he sees a rabbit and suddenly bolts after it (which is why I got this), a maximum shock setting of 100 has no effect whatever. There is no indication he even notices it. I will likely return this. A minor issue-- my Aussie is a medium-sized dog (about 50 lbs) but I have to adjust the collar to as small as it can go to fit him. It seems to be sized for a mastiff or something, not an average size dog.