Amazon.com: Anti Barking Device, 1500 mAh Rechargeable Ultrasonic Dog 2 Pack Anti Barking Device, Dog Barking Control Devices up to 50 ft I Tested the Top Ultrasonic Dog Training Devices and Heres What Happened! Amazon.com : Ultrasonic Dog Bark Deterrent, Ultrasonic Anti Barking Anti Barking Device, Handheld Ultrasonic Dog Barking Control Devices 16 NPS Ultrasonic Dog Bark Deterrent, Indoor Outdoor Bark Control Device. Product features: 1. An ultrasonic anti barking device can automatically detect dog barks 50 feet away. The barking control device automatically emits high sounds that only dogs can hear. After the dog stops barking, the ultrasonic barking control will automatically stop emitting an ultrasound. 2. Ultrasound is harmless to pets and completely inaudible to human ears, so the device can be used safely 3. Can be hung on a tree, indoor, or outdoor wall, or fence to prevent dog barking (within range). When the luxurious outdoor ultrasonic barking alarm clock detects excessive barking, the microphone will respond to the barking and activate components. 4. Suitable for dogs from 6 months to 8 years old. Packing list: 1 x Anti bark device 1 x USB cable 1 x Instruction book Looking for more options? Explore our full collections to find styles you??? ll love. And Visit our Canadian Store