Features: 1. Train Dog Whistle: By adjusting different ultrasonic frequencies, you can easily teach your dog unlimited commands. To adjust the pitch for the correct frequency, loosen the sonic adjustment screw while blowing from the air intake, and turn the adjustment lever to suit the optimum pitch. After turning the adjustment lever, tighten the sonic adjustment screw. This dog whistle can be used on any common breed of dog. 2. When your dog or your neighbor's dog is barking nonstop, blow the dog whistle gently, and the ultrasonic frequencies emitted by the dog whistle can easily attract the dog's attention and stop the barking. 3. Safety whistle: The dog whistle produces a background frequency range of 5.4 KHz to 12.8 KHz while rotating. However, dogs whose ears are more sensitive to this frequency may not be critical to human hearing. 4. Effective dog training: Your dog can hear you from 200 feet away. This ultrasonic siren can keep your dog from getting lost. Train your dog with different commands to follow your directions. (Sit down, paw, lie down, get up, get down.) Description: Name: Training Whistles Product Category: Dog Trainer Material: Stainless steel Product size: total length 9cm, flute length 8cm, lanyard folded length 42cm, width 1.5cm Packing list: 2 x Training Whistles Note: Different displays may cause the color of the item in the picture a little different from the real thing.  Manual measuring,please allow 1~3mm error,thank you.