PetZoom™ Sonic Pet Trainer provides a humane pet training system that uses a high frequency ultrasonic pitch that only dogs and cats can hear. Sonic pet trainer is the effective way to develop positive behavior in your pet. Emits a high frequency ultrasonic pitch that commands your pet's attention and helps them obey your commands. The sound is silent to people, but clearly audible to dogs and cats. Helps reinforce verbal commands such as sit, stay, down and quiet. Effective up to 20 feet away. Easily teach your pet commands or use it to keep animals away.