?- 45 ?-This bark control unit is equipped with USB data cable, fully charged for about 5 hours, and can be used continuously for up to 5-7 days. with a working indicator light, you can easily check the working status of the battery. When it 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. ?- - ?-This dog bark control device only works when the dog is barking, which can calm your dog and 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. (Some dogs may be afraid or dislike ultrasound and they won't stop barking at first. Please allow up to 2 weeks for training.). ? 16.4 ?-The dog barking controller uses the latest sound sensor technology to intelligently capture dog barking 16.4 feet away, a small distance is more suitable for indoors, and automatically emits ultrasonic decibels to distract the dog to stop barking. (The effective distance will be shortened indoors or in places with obstacles). ?3 ?-This dog barking control device has 3 different levels of ultrasonic, (10-15KHZ) suitable for Small dogs. (20KHZ) works on docile dogs. (30KHZ) is more friendly to large naughty dogs. You can choose the appropriate mode according to your dog's specific situation to achieve the best results. (Not suitable for hearing-impaired dogs or for use on two or more dogs at the same time.). ? 4* ?-To address the problem of insensitive ultrasonic waves, we have adopted a remedial measure: adding 3 ultrasonic waves to the same device, so 4 ultrasonic waves work at the same time. The dog will be more sensitive and stop barking!.