Product description< Battery: 4 AAA batteries (not included)< Effective distance: 5m< Material: ABS< Product size: 4.2 X 3.3 X 9.5cm< Color: army green, black< Package content: 1*ultrasonic dog repeller< 1.EFFECTIVE TRAINING DEVICE- The ultrasonic bark control device can not only prevent dogs from barking but also instruct their uncivilized behavior. You can correct unwanted behavior such as jumping up, digging, chasing, trash raiding and excessive barking. This can change your pet's bad habit of barking under the principle of ultrasonic sound.< 2.EASY TO USE- Just only push of a button then it emits an ultrasonic sound which can only be heard by the dog. The ultrasonic sound frequency is 25KHZ for maximum and effective range is 5 meters. It produces a high-pitched ultrasonic sound that is irksome to dogs and at the same time it is soundless to the human(the audibility is limited to 20KHZ). It is fully harmless and safe to humans and dogs.< 3.CONVENIENT TO CARRY It is small and lightweight and fit perfectly in your pocket, designed to be convenient to carry around with you. Suitable for indoor use and walking the dog outdoors as well. Made by high performance ABS material and waterproof. The LED light on top of the button can indicate working status and low power mode.< 4.SUITABLE FOR ALL SIZE DOGS- The ultrasonic dog bark deterrent has 2 different levels. One simple button to operate, suitable for small, medium and large dogs(from 6 months to 8 years old).With a frequency button, you can adjust the ultrasonic frequency according to the dogs condition conveniently. We recommend you start with the unit on low and then increase the power as needed.< 5.FRIENDLY NOTE- The anti bark device may not effective on dogs who are hearing impaired and old. We recommend using this ultrasonic bark control on dogs above 4.5lbs. Do not use on aggressive dog.