Safety Design: The barking deterrent range can up to 16 feet and be turned off as a safety function after 10 seconds. Item Type: Ultrasonic Anti Barking Device. 1 x Ultrasonic Anti Barking Device. Electronic Dog Whistle: With sound and 3 ultrasonic modes, the frequency is 25 to 30 kHz, which is hard for human to hear, specially for dogs.
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