1. 100% safety control device.Ultrasonic frequency is harmless to pets and has no effect on human ears. A harmless and humane way to keep your dog and neighbor's dog from barkingEffective for all breeds and all dog breeds. 2. How it works.With the help of the internal microphone to pick up the dog bark, the dog bark device is automatically activated when it detects the bark. Then it will send out an ultrasound to quiet the dog. When the dog stops barking, the ultrasound will also stop. 3. 4 adjustable sensitivity.The anti-bark device has 3 range levels and a test mode. Including: low sensitivity (15 feet), medium sensitivity (30 feet), high sensitivity (50 feet). 4.Waterproof and durable.Ultrasonic anti-smashing, durable, weatherproof, sturdy dog skin control, lightweight, waterproof material, it can be safely used indoors and outdoors in any weather conditions. 5.Mini design.This ultrasonic anti-barking controller adopts a well-designed mini shape, which can be hung on trees, indoor and outdoor walls or fence posts to prevent any dog barking (within range) 6. Battery type: 9V battery for battery type (not included)"