3-in-1 training and anti barking device: Zttopo dog gentle anti barking device provides a safe and effective way for dog training and bark control. With an ultrasonic releasing mode, a beep training mode and LED flash light mode, the dog anti barking device can effectively train your dogs to stop unwanted behaviors like barking, digging, clawing, biting, scratching, and getting on furniture, easy peasy 3 ultrasonic frequencies wave is suitable for all size dogs: Stimulates dogs through sound that humans can’t detect and won’t hurt the auditory sensors of pets or other animals for safer daily use. Fixed frequency: Giving the dog continuous stimulation; Variable frequency: changes regularly and works in a sweep frequency mode; Random frequency: changes randomly, which can better match most dogs Long control range & usb rechargeable: Ultrasonic sound device is effective in the range of 32.8ft which make it more convenient to training them to behave well in public and protect them from eating unsafe food. The built-in battery with 1200mAh capacity can be fully charged in 2 hours supporting 20 days of regular use. It's very suitable for short-distance travel, indoor or outdoor activities, saving you endless hassle and invest in batteries