Dogs can hear sounds that are inaudible to the human ear. The higher sound frequency produced by this whistle will enable you to train your dog to obey your commands. Once you train your dog to respond to a specific pitch the locking nut on this whistle can be screwed down to ensure the same pitch is reproduced each time. Please note that this whistle is not completely silent to the trainer. Approximately 3-1/4 inch long with a small ring to attach to a key chain. |