Quantity: One Ultrasonic Dog Trainer Using the latest ultrasonic technology, Wango Barking Trainer is suitable for dogs of different breeds and sizes. The ultrasonic frequency is harmless to pets and humans. It can be used as a dog repellent and dog training aid to stop bad dog behavior such as endless barking, searching and fighting. [Portable anti-bark design] This device dog bark control is lightweight, very suitable for putting in a pocket and suitable for indoor and outdoor use. Equipped with a hand strap, easy to carry. Press the button of this bark control device, it will emit ultrasonic waves, at the same time, the green light indicates the device is working, and the red light indicates the device needs to be charged. [Rechargeable Dog Bark Controller] Our newest version of ultrasonic dog bark controller makes training your dog easier. Comes with a USB cable, the anti-bark plug can be fully charged in 5 hours and can work continuously for 15 days. Compared with other similar products that require batteries, our products are more environmentally friendly and save money. [Dog Barking Effective To Deter] The control range of our bark control device can reach 16.4 feet and it emits 24kHz ultrasonic waves. This sound will not affect humans (hearing limit is 20kHz). With beeps and ultrasonic, it can easily attract dog"s attention and improve bad behavior. Continuous training is necessary to achieve effective and long-lasting results. [Suggestion and service] Whenever your dog does pranks by barking, leashing, jumping, etc., just press the button and point the ultrasonic dog training selector directly at it. Once he has a positive reaction, praise him and reward him to strengthen his memory.Good quality product