Hagen Dogit High Pitch Silent Dog Whistle

About the Product:

The DogIt Silent Dog Whistle by Hagen is a high pitch training whistle with ultrasounds. It's more effective than your voice! Your dog will hear the high-pitched whistle from a farther distance and you don't have to strain your vocal chords by shouting.

Of course, you must train your dog first to know how to react when they hear the whistle.