Professional Dog Whistle Adjustable Pitch: Loosen the sonic adjustment screw while blowing air in from the air inlet. Turn the adjustment lever to find the optimum pitch. Once adjusted, tighten the sonic adjustment screw. Compatibility: Suitable for use on any common breed of dog. Safe Dog Whistle Materials: Made of durable stainless steel. Health Considerations: Silent whistle for dog training without health concerns. Ensures your dog's hearing is not hurt during training sessions. Sound: You will be able to hear the sound too. Anti-Loss Whistle Design: Crafted with stainless steel and coated with a protective lid. Protection: Prevents dirt, damage, and accidental loss. Ease of Use: Comes with a matching black lanyard for easy wearing around your neck. Easy Dog Training Frequency Adjustment: Adjust the frequency by turning the screw rod inward or outward. Find the frequency that elicits the strongest reaction from your dog. Training Benefits: Once the correct frequency is found, the whistle can ensure your dog obeys basic skills through sound after training. Silent Ultrasonic Dog Training Whistle Frequency Range: Produces sound frequencies between 5.4 kHz and 12.8 kHz. Sensitivity: Dogs are much more sensitive to this frequency range. Human Perception: The sound is not too loud and may not be clearly heard by many people. Dogs, however, are far more sensitive to these frequencies than humans.