The High Tech Pet Super Hush Puppy Sonic Bark Control Collar is an advanced dog training collar that automatically increases sonic output until your dog is quiet. A super effective anti-barking collar that emits progressively increasing sound intensity as your dog's barking persists. Sound level is automatically increased through four intensity levels and automatically resets once barking ceases for more than thirty seconds. The use of our unique progressively increasing sound stimulus is more effective in stopping barking because it quickly teaches your dog a pattern which is in direct response to the animal's behavior. This technique is guaranteed to stop your dog from barking in the fastest time possible without painful shock.