Pet-friendly ultrasonic anti-barking device for dogs. This device emits a stable frequency that only dogs can hear to deter barking. No spray, no electric shocks. Harmless to human and dog hearing, helping create a quieter space for dog lovers while stopping unwanted behavior. Key benefits - Effective for dogs of all sizes with 3 adjustable sensitivity and frequency levels: 15-30 kHz for large dogs; 20 kHz for medium dogs; 30 kHz for small dogs. Adjust weekly to maintain training effect. Control range up to 33 ft (10 m). - Easy to use: Rechargeable anti-bark device with light indicators. At each level, blue light flashes every 6 seconds; red light stays on for 3 seconds when barking triggers the device; red light also flashes at low power. - Battery and efficiency: 3.7 V 1500 mAh battery. A 5 hour full charge can provide up to 15 days of use, reducing frequent battery swaps. Outdoor and indoor use - Built with IP4 rain protection and a portable hook. Hang easily on trees, walls or fence posts for outdoor use; indoors, place on a desk, wall or shelf at a height of more than 1.5 m to maximize effectiveness against barking, digging, and fighting. Use scenarios - In the yard to deter your dog from constant barking during play or when guests arrive. - On patios or around the garden to reduce barking noises during outdoor gatherings. - Indoors to create a calmer environment by positioning above eye level, helping with barking when visitors arrive or during conflicts.