Steps to use: Loosen the black handle and turn the sound adjustment screw. Rotate the adjustment lever while blowing air from the air inlet to set the optimal incline. After rotating the adjustment lever, tighten the clamp adjustment screw.Material: The training whistle is made of plastic and is attached to a braided cord with a snap hook. The braided cord is made of 100% polyester. The dog whistle is made of a robust weatherproof material. 100% safe, strong and durable. The ultrasonic dog whistles do not affect your dog's hearing. Very suitable for training dogs.EASY TRAINING: Our dog whistle reliably stops barking and helps in learning commands and tricks. Teach your dogs obedience and many commands like B. Sit, Come, Stop Barking, Stay and Toilet TraininAjuatable Frequency: Our ultrasonic dog whistle trains dogs to perform different actions by making sounds of different frequencies. It should be noted that every time you whistle, you need to pay attention to the dog's reaction, so you can slowly train the dog, get acquainted with the sound and take appropriate actions.