1. Unique Design Ultrasonic Bark Stopper Unique design for ultrasonic waves, not harmful to dogs or people. Its sound wave is a gentle but effective deterrent that can make the dog quickly quiet down, attracting your dog's attention and encouraging them to stop barking. Its ultrasonic waves are made for dogs, and the appearance of the design is like an alarm clock. 2. 4 Modes of Ultrasonic Adjustment Bark Box has 4 modes to adjust the frequency: Ttest mode, 1 low range up to 15 feet, 2 medium range up to 30 feet, 3 high range up to 50 feet. When the dog barks, the red light flashes to show that the ultrasonic is working. The green light flashes after the dog stops barking to wake up. The red light flashes when the battery is low. 3. IPX4 Safe Anti Barking Devices The Bark Deterrent is housed in a professional IPX4 waterproof enclosure, can withstand any bad weather and work normally. Its robust design makes it an ideal option for outdoor settings. When barking is detected, the antibarking device emits harmless ultrasonic waves. This bark stopper has a small and lightweight appearance, and you can carry it with you for outdoor use when outdoors. 4. Applicable Range Effective in controlling excessive barking, ideal for apartments, condominiums or homes with nearby neighbors. We can place it on the wall, fence or tree. Any location indoor or outdoor is fine. Its sound waves can reach up to 50 FT, preventing your neighbor's dog or even stray dogs from barking excessively.