Dog training collar review
One important thing to keep in mind when buying a dogis that the regulations which manufacturers have to follow when researching, producing and marketing their products are not uniform internationally. So one product made in the USA might not meet the specifications of a product made in England. Another thing I discovered when doing my dog review was that when one company says that their static electric shock anti bark collar does not hurt the dog, it is not necessarily true. The reason for this is that again the regulations are not uniform and one shock anti bark collar might give a significantly higher voltage shock than another. I found the same with the sonic anti bark collars. One company claimed that the sound emitted by their unit was outside of the human ear's range while another company said that the correctional sound was only "mostly" outside of human hearing. Now what this means exactly to the dog is difficult to know.
Probably the safest non electric anti bark collar which I came across when doing my dogreview was the spray collar. This device uses an allegedly harmless spray that is not injurious to the dog nor highly offensive to humans.