The unit is very easy to use and can be programmed to operate on a timer. The three range levels allow you to customize the sound level to your specific needs, and the test mode ensures that the device is working properly. Category All Products (4718); Bird Cages and Aviaries (21); Cat Containment and Deterrents (11); Dog and Puppy Health Fitness and Safety (37); Dog and Puppy Kennels and Pens (10); Dog Bark Control (8); Dog Houses (2); Dog Ramps and Steps (12); Dog Tracking Collars (8); Dog Training Collars (21); Dogs and Puppy Car Seats (4); Electronic Dog Fences (7) It simply doesn't work. It comes with 4 range levels to choose from and can even detect a dog barking 50 feet away.