Pet's House Dog Whistle Professional Stop Silent Bark Train Dogs & Promote Obedience with UltraSonic Bark Control & Adjustable High Frequency & Durable Lanyard & Tight Grip Cover NECESSARY: when go outside for a walk or a trip,your dog may be excited and run arroud.You can give him/her instructions easily with this whistle. EASY DAY TRAINING  adjustable to multiple frequencies  easily teach your dog unlimited commands such as sit, come, stop barking, stay, and more every day. Give your dog praise and reward(such as snacks,massage) when he/she follow your instruction. HOW TO USE: Starting out, blow the whistle to test your dog's response. Unscrew the bottom of the whistle and adjust the internal screw until your dog responds to the sound. Check for a helpful perk of his or her ears. Tighten the locking nut to lock that frequency in place. It's important to always use the same frequency. PERFECT DESIGN AND SIZE: Nickel-plated, brass whistle with a frequency that carries a long distance. Pet Prime's whistle is built to be with you wherever you go - on your keyring or around your neck NOTICE: This whistle is a tool used for dog training.Follow the steps in our picture description to adjust the whistle to a appropriate tune,and then train your dog.