SPECIFICATIONS & Anti-bark device& The ultrasonic bark Deterrent adopts high-frequency sound, which can reduce the excessive barking of dogs in the hearing range. When you hear the dog barking, press the ultrasonic control button. The anti-barking device emits ultrasonic waves to attract the dog's attention and prevent it from barking excessively & Definite Safe for Dogs and Humans & When the speaker emits ultrasound, this sound wave can only be heard by dogs and will not cause influence dogs and the human body. Dogs should stop barking after being stimulated by safe and effective high-pitched sounds. & Dog Training & Our dog barking deterrent devices provide a safe and effective solution for dog training and bark control. The ultrasonic dog bark deterrent can effectively train your dogs from behaviors such as barking, digging, eating unknown food, fighting, etc. & Standard frequency and frequency conversion can be set to deal with different kinds of dogs. If the dog is not sensitive to the ultrasonic standard frequency, switch to another frequency. & Attention& It may not be suitable for dogs with hearing problems, dogs under 6 months or over 8 years, or aggressive dogs. Note: 9V Batteries ( NOT INCLUDED )