✓ Rechargeable-IPX4 Waterproof?This bark control unit is equipped with a USB data cable, fully charged for about 5 hours, and can be used continuously for up to 5-7 days. And with a working indicator light, you can easily check the working status of the battery. When the 3rd gear is working, the indicator light on the anti-bark device flashes blue every 6s; when the dog barks triggers the anti-bark device, the red light stays on for 3s; when the battery is low, the red light flashes. ✓ Multiple Hanging Hole Design?There is a small rotatable hook at the top and rear of this bark suppressor, which can be hung on trees, walls or fences; there are 2 holes embedded in the rear of the body, equipped with a punching device, easy Install. ✓ Safe-Humane Anti-barking Device?It only works when the dog is barking, which can provide a quiet sleeping environment for your family and neighbors; the ultrasonic wave of the anti-bark device Harmless to pets, completely inaudible to human ears. When the bark stopper handles the dog's barking, it can be assisted by training to gradually reduce the barking. (Some dogs may be afraid or dislike ultrasound and they won't stop barking at first. Please allow up to 2 weeks for training.). ✓ 3 Levels Adjustable Ultrasound?This dog barking control device has 3 different levels of ultrasonic, 15KHZ is suitable for large naughty dogs. 20KHZ acts on docile dogs. 30KHZ is friendly to small dogs. You can choose the appropriate mode according to the specific situation of your dog to achieve the best effect. (Not suitable for hearing impaired dogs, nor will it work on two or more dogs at the same time.). ✓ Effective Range Up To 33 Ft?The dog barking controller adopts the latest sound sensor technology, intelligently captures dog barking up to 33 feet away, and automatically emits ultrasonic decibels to distract your dog's attention to stop barking. (The effective distance will be shortened indoors or where there are obstacles).