Product name: Ultrasonic dog whistle. Product size: 9cm Product color: black Delivery quantity: 3 pieces Product material: metal + plastic High-quality materials: Dog whistle made of high-quality stainless steel, not easy to rust and deform, will not harm your health or your dog. Adjustable frequency: Adjustable to multiple frequencies, which is conducive to the dog's obedience and basic skills training. Professional dog whistle: The dog whistle diffuses sound through high-frequency sounds. Rotate the adjustment lever to adjust the best tone frequency. Easy to use: By adjusting the nut and adjustment rod for sounds of different frequencies, you can observe the dog's response to each sound for better training. Our combination is small and can ensure comfortable operation. Note: The data are all manual measurements, please allow an error of 1 - 3cm, due to the difference in light and display, there will be a certain color difference, whichever is the actual physical object received