Adjustable ultrasonic silent dog training whistles.
When you can't make a sound,not that the whistle doesn't work,it's because you haven't adjusted the frequency properly.The correct usage method: You should unscrew the pole,continuously adjust the nut and blow it,adjust it to the most suitable response frequency for your beloved pet.Only then can you effectively training and summoning.
Easily train the dog,sit down,shake hands,stop barking,other commands.