The Premier Pet Dog Trainer helps you improve behaviors in your dog small or large by allowing you to communicate and effectively enforce the rules in a way that is easy for your dog to understand. Three options for training: tone vibration and 16 levels of static stimulation. The rechargeable training collar has a nylon strap that is adjustable up to 28?. This training system can be expanded providing an effective training tool for up to two dogs using the same remote.