The Sonic Pet Trainer from Pet Zoom is the most effective way to teach your pet good behavior. Safe and effective. Works with all dogs and cats. The Sonic Pet Trainer is silent to humans, but its ultrasonic pitch is clearly audible to animals, getting their immediate attention and making your pet immediately obey your command. Stop chewing, biting, excessive barking, jumping on furniture, or any unwanted behavior. Never harms your pet. Effective up to 20 feet to keep unwanted animals away when you’re outside.