Come and see our amazing products. While the average hearing frequency range for human is 20Hz-20KHz, the dog's hearing range is 15hz-120khz. This anti-barking device emits 25kHz sound wave, which will not affect human beings, but will cause the dog's attention. Therefore, it is very safe and user-friendly. The dog barking deterrent combines bark controller with dog training, which can effectively train your dog to be obedient, correcting barking, digging holes, fighting and other bad behaviors. The handheld dog training tool can be used to train dog's defecation, sitting, standing, jumping and other trainings. Besides, when you jog, walk, ride a bicycle, or wait in the park or in the car, etc., it can be used to drive away unfriendly dogs. The device works with 9V battery (included). Pls confirm further with us if any query about packing info, inventory status and time schedule.