Adjustable Frequencies: Different dogs respond to different frequencies. Our dog training whistle has a nut and screw that can adjust the frequency when turned. Note your dog's reaction at each setting until your dog exhibits the loudest reaction.Easy Dog Training: This is a great tool for teaching your dog obedience and learning basic skills. Train your dog with the ultrasonic whistle so you don't need to shout loudly.Effective Dog Training: Your pet can hear the whistle up to 25 meters away, even if they can't see you. Train your dog with different commands and make them follow your instructions. (Sit, Paw, Lay Down, Up, Heal)Anti-lost whistle: The body of the dog whistle is made of stainless steel with a protective cover to prevent dirt, damage, and accidental loss. It is extremely easy to wear around your neck with our matching black lanyard.Note: Please note that this puppy training whistle will not allow your dog to understand your instructions immediately. It requires multiple trainings for your dog to listen to your commands. Use the positive behavior approach to train your dog to be a good listener and obedient friend. When the dog is 3-7 months old, the training effect is the best.Number of pieces delivered: 2Color: BlackSize: whistle 8 x 0.7 cm; lanyard 49 cm.