DLAND Two Pack of UltraSonic Dog Training Whistles - Ultimate Whistle to Stop Barking - Best Silent Dog Whistles with Adjustable Frequencies to Change Sound & Pitch HELP YOUR DOG OR OTHERS TO STOP BARKING - Distract your dog from their barking spree and distract them from whatever is causing the barking or other unwanted behavior. Dog whistles are a perfect training tool to teach keep quiet. Professional dog trainers agree it's still the most effective way of communicating with their dogs. TWO-PACK OF WHISTLES SO YOU ALWAYS HAVE ONE HANDY - Why only get one dog whistle when you can get two for the price of one? TRAIN YOUR DOG THE RIGHT WAY - Dog Whistles have been used over a 100 years, still the most effective tool for training. Use the dog whistle with changing orders. One long burst can mean 100% LIFETIME GUARANTEE - You heard that right! No questions asked, 100% lifetime guarantee on these dog whistles! ULTRASONIC DOG WHISTLES ARE THE BEST DOG WHISTLES - Emits frequency that your dog can hear from far distances to recall. Just adjust the pitch and blow the whistle to your dog. Wait until he is asleep and gently blow on the whistle. Continue to test the whistle until your dogs ears perk up, your dog whistle has a nut and screw that you can adjust and lock the frequency.