Package includes: you will receive 5 pieces high pitch plastic dog whistles in 5 colors, including black, orange, blue, white and green with 5 pieces black strap lanyards and key rings in black; Enough quantity could satisfy your daily using and replacement needs, or you can share with your friends or families who are in need of it Nice tool for dogs training: the 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 training Dogs training tool: dog whistle allows you to easily train your dog/ puppy, such as stop barking, sit, come, and lay down, recall, toilet training and more; The plastic dog whistles are nice tools for you to teach your dog obedience and learn basic skills; Use the dog whistles to train your dog so that you don't need to worry about controlling your pet Safe material and design: the dog whistle is designed with compact size and comes with firm black strap lanyard with quality metal and hard plastic; It will not hurt your dog's hearing and also be harmless to our humans, which are safe and can serve you and your dogs for a long time, and the compact design size of the dog training accessories allows you to carry them conveniently Adjustable sound frequency: different dogs respond to different sound frequencies; 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