Anti-bark Ultrasound Device, Controllable Frequency Adjustable Bark Dog Sonic Device Anti-bark Control System.New version of the anti-bark device Frequency adjustment in two steps: & It can switch the frequency conversion mode of the ultrasonic level for a more obvious training effect when your dog is desensitized to the standard frequencyPortable and practical With adjustable wrist strap which is portable and portable, also convenient to carry anywhere, such as jogging or walking, cycling, park, etc The effective range is 5 meters100% safe for you and dogs The average frequency range of human hearing is between 20Hz and 20kHz The frequency range of dogs is between 15 Hz and 120 kHz It produces a high level of ultrasound which can grab the dog's attention and stop bad behavior, but is harmless to humansMulti-functions Except as a pet training tool, it can also prevent dog attacks, suitable for training many kinds of dogs, such as pets, police dogs and shepherds, suitable for outdoor work, travel and night security patrolsBell Control For Dogs Works acoustically distracted, 100% safe for humans and animals When training your dog with this product, it is best to cooperate with the voice training of the masterEasy to use