Optimal for training and education. Five metal discs on a nylon strap allow for effective training using the SignalTone method. Chrome-plated, includes a practice booklet with tips and tricks for optimal training. By using these five discs, you train your dog to respond to an acoustic signal that means "Stop. I don't like that." Training your dog is based on the following principles: 1. Dogs primarily respond to sounds and acoustic signals rather than language. 2. Dogs learn more easily when the sounds and signals remain consistent. 3. A reward for correct behavior trains your dog better than a punishment for unwanted behavior. 4. The absence of a reward is the greatest punishment for your dog.