This ultrasonic dog trainer is a professional equipment for dog training and barking control. It emits 15KHz-40KHz safe frequency sound waves that attract the attention of dogs and prevent unwanted behaviors such as barking, digging, scratching, biting, and climbing on furniture. The device has a sound wave transmission distance of up to 32 feet and is compact enough to fit in your pocket or bag, making it easy to carry around and use outdoors and indoors. It is rechargeable with a built-in 800mAH Li-ion battery and USB/Type-C charging port, and can be fully charged in 0.5 hours for 90 days of use. The device has two sonic modes, a low-frequency mode for daily bark training and a high-frequency mode to immediately curb bad behavior, as well as an LED burst light for safety at night.