Ultrasonic Pet Anti-Barking Device Dog Bark Control Stop Repeller Silencer Training Tool Feature: Pet friendly anti-barking device: this ultrasonic barking control device works by sending a stable frequency sound that only dogs can hear, preventing dogs from barking and calming dogs. No irritating smell, no electric shock, anti-barking for dogs that only work when dogs bark. Bark repellent device is harmless to the hearing of people and dogs, perfect to create a quiet department for dog lovers and stop unwanted behaviour. Effective for dogs of all sizes: the ultrasonic dog barking repellent with 3 adjustable sensitivity and frequency levels (15-30 kHz for large, naughty dogs); 20 kHz for educational dogs; 30 kHz for small dogs) prevent dogs of different sizes from barking easily. Adjusting the frequency for each week can maintain the training effect. Easy to use: this rechargeable dog bark control device with LED indicator can be used effortlessly. When you work on 3 different levels, the light flashes blue every 6 seconds; red light stays on for 3 seconds when the sound barking is triggered; the red light flashes at low power. Outdoor and indoor use: the human bark devices with IPX4 rain protection function and the portable hook can be easily hung up trees, walls or fence posts. But when heavy rains, it&39;s best to bring it back to extend its lifespan. The ultrasonic dog device can be placed on a desk, wall and shelf with a height of more than 1.5 m, which can be adjusted more effectively for barking, digging, fighting, etc. Material:ABS Package included: 1 * Anti-Bark Device Control 2* Mounting Screws and Anchors 1* USB Charging Cable 1* User Manual