PROFESSIONAL DOG WHISTLE You can adjust the pitch to get the right frequencies, loosen the sonic adjustment screw while blowing the air in from the air inlet, turn the adjustment lever to adjust to the optimum pitch. After the adjustment lever is turned, tighten the sonic adjustment screw. This dog whistle can be used on any common breed of dog. SAFE DOG WHISTLEOur silent dog whistle is made of durable stainless steel, training your dog without any health concerns, it doesn't hurt your dog's hearing during training sessions, please to know you will hear the sound too.ANTI-LOSS WHISTLEThe dog whistle body is crafted with stainless steel coated with a protective lid to prevent dirt, damage, and accidental loss. It is extremely easy to wear around your neck with our matching black lanyard.EASY DOG TRAININGthe training whistles could adjust frequency by turning screw rod inward or outward until your dog exhibits the strongest reaction; With the correct frequency you find, the dog whistle can ensure that your dogs obey basic skills through sound after trainingSILENT ULTRASONIC DOG TRANING WHISTLE Dog whistle produces a range of sound frequencies between 5.4 kHz and 12.8 kHz when you adjust it; Dogs are much more sensitive to this frequency; The voice of the dog whistle isnt too loud; Many people cannot hear the sound of whistle clearly, but dogs can, which are far more sensitive to this frequency than humans