Dog Barking Control and Dog TrainingOur ultrasonic anti-barking device provides a safe and effective solution for dog training and barking control. A bark guard can effectively train your dog to stop barking, digging, eating unsafe food, fighting and other unwanted behaviors.[Applicable] The average hearing frequency range of humans is 22HZ~20KHZ, and the range that dogs can hear is wider, from 15HZ to 120KHZ. Our ultrasonic barking control emits ultrasonic waves of 22-25KHZ, so the sound will not affect humans, but can attract the attention of dogs.EASY TO USEOur ultrasonic barking dog deterrent fits your hand perfectly and comes with an adjustable anti-static wrist strap. When we use ultrasonic technology, it is effective for dogs of all sizes up to 16.4 feet.Portable Size and RechargeableThe device fits perfectly in your hand. It comes with an adjustable anti-static wrist strap and an electronic dog repeller with a rechargeable lithium battery; no batteries required. Just press and hold the button and the bark deterrent emits ultrasonic waves to attract the dog's attention.Note: Not suitable for hearing-impaired, aggressiveDogs under 6 months or over 8 years old