Ultrasonic Dog Whistle Different dogs respond to different frequencies. Our dog training whistle has a nut and screw that would adjust the frequency when turned. Notice your dog's reaction to each setting until your dog exhibits the strongest reaction. BEST DOG WHISTLE FOR TRAININGThis professional ultrasonic whistle is a great training aid for any dog, at any age. It will ensure you have their full attention whilst training and they can hear you for huge distances Let your dog follow your instructions of stop barking, sit, come, and lay down, recall, toilet training. 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. NotePlease keep your whistle command consistent, you should reward your dog If it responds positively. When the dog is 3 to 7 months old the training effect is the best. CHOOSE A BETTER ECO-FRIENDLY DOG WHISTLEThe simply natural dog whistle crafted cruelty-free and safety tested with your pet in mind.100% SATISFACTION