" Bark Control Device: At the push of a button, the device emits ultrasound that can only be heard by dogs. Instantly help stop bad dog behaviors like barking and searching. Safe for humans and dogs. Easy to Use: Intuitive 1-button design prevents incorrect operation. Just press the button to activate the ultrasound. Press and hold the button to continue sending ultrasound. The maximum working time is 10 seconds each. Convenient to Carry: The dog bark controller confirms the ergonomic design and fits well in the palm of your hand. With the help of the mini dog trainer, you can easily take the bracelet with you everywhere. Ultrasonic Transmitter for Dogs: With a valid range of 5m / 16.4ft, it can be used as a great aid to deter stray dogs from approaching you or your pet. Stay clear of conflicts and dangers. What you get: Ultrasonic transmitter, wrist strap, user manual and 100% satisfaction guarantee. Contact the customer service center if you have any problem and we will help you