It is not the best solution to the barking problem, but it is the fastest. My dog made in 3 days and stopped barking whenever I leave the house. I tried the intensity of shocks personally and to level 4 does not hurt and is more than enough for the dog to know that he should not bark. With this intensity I do not consider this cruel, the dog is simply afraid. I have not had to use at a higher level than the 4. Excellent product, even if the battery is longer life
