[Safe & Friendly for Animals and People] - This dog silencer ultrasonic bark control decive has been tested and proven to be completely harmless to humans animals and plants. Because of its precise sonic frequency, you may not even hear it! Itll take up to 2 weeks for the barker to learn what the piercing noise means.[Effective Range Up to 50 Feet] - Our dog barking control devices outdoor were conveniently designed with multiple settings; The multi directional microphone picks up dogs in any direction! Mode 1: Low Range (up to 15 feet); Mode 2: Medium Range (up to 30 feet); Is it further away? Mode 3: High Range (discourage all dogs outside up to 50ft.).[Easy to Use] - Dog Bark Deterrent Devices has a built-in pickup that can detect the dog's barking within 50 feet and automatically emits ultrasonic that the dog can hear. Once the dog stops barking, the device automatically stops. Compared with the traditional dog training device, it completely frees your hands. Automatic and effective training your dog to stop excessive and noisy barking.[Waterproof] - Dog Barking Control Device has IPX4 waterproof, the case is UV resistant and not easy to fade. Designed to be easily hung/installed on trees, walls or fence posts to stop any dog barking (within range), indoors, outdoors, etc. anywhere. The dog deterrent device is not suitable for aggressive dogs and hearing impaired dogs.[Energy Saving] - Operates 9-Volt batteries (not included), average battery life 5-6 months depending on use. It can be started with a 9V battery (not included). Keep it at arm length, then whistle into the microphone. The device will beep and the LED will flash green.