This training system is specifically designed for hard to train, stubborn dogs. You know some dogs are not sensitive to other kinds of training signals. If you want to get your dog's attention, this is the solution. It's fit for small/medium/large size dog as long as your dog's neck suits the adjustable collar length. This remote training shock collar has 6 levels of strong static shock and 1 level of vibration. It is an electronic dog training system with a working range up to 600 feet. This compact, easy to operate system will control bad behavior and dogs who run off when taken outdoors for exercise. NOTE: The battery life depends on how often you use the collar. When you are not training the dog, please take it off from the dog to save battery. Don't wear it on the dog all the time. The supplied 6V battery is for start-up purpose only and may not last long (2 to 3 days) depending on how often you use the collar.