This dog training whistle can help you. Train your dog and eliminate or stop dog barking while obeying basic commands. Easily adjust the frequency to your dog. You can use the adjusting screw to make sure. That the selected step remains defined. Light and compact with key ring. Fits the palm of your hand. You can hang the training whistle with your keys and carry it anywhere. Where to goWith this small, high-quality whistle you will always find the optimal frequency, especially for your dog. Whether for training with puppies or older dogs. The whistle operates in the high frequency range and is therefore not particularly loud to humans. But very audible to dogs.