No noise for others: The dog whistle can emit ultrasonic waves. The dog can hear the ultrasonic waves emitted by this whistle, but people can't, so you don't have to worry about disturbing others when whistling.Dog Whistle The ultrasonic dog whistle will not harm the dog's hearing, so you can use this whistle to prevent the dog barking or train the dog to perform various actions.Anti lost dog whistle: A high quality lanyard can help you wear it around your neck, you will never worry about losing it.Easy to Use The dog can clearly distinguish the ultrasonic waves emitted by the dog's whistle, and the owner can use the dog's whistle to give different instructions to ask the dog to do different actions.Note: This dog whistle will not give your dog instructions immediately. You need to train your dog with this whistle so that the dog can understand your orders. We recommend that you use motivational methods to train your dogs and make your pet a well-trained friend.