ith the help of the ultrasound, you can train your pet to be obedient, corrects misbehaviour and stops barking Convenient for you to carry anywhere you need, such as jogging or walking, cycling, park and so on The sound is audible only to pets, finally turn on and it can work well, also they can serve as a flashlight when necessary Provides 3 in 1 anti barking handheld dog training device