Quantity: 3 pieces Your dog's excessive barking can be a bit frustrating. If they haven't received training, it's almost impossible to calm them down. Training your dog to recall is one of the most important things every pet owner should do. One of the best and easiest ways is to use a dog whistle. This set of 3 high-frequency training whistles is suitable for recalling working dogs and domestic dogs. This dog whistle will help you control dog barking easily and effectively. The frequency of this whistle is so high that only dogs can hear it, so you don't have to worry about annoying high-pitched noises. This dog training whistle is an excellent tool to promote effective barking control. Professional dog whistle: You can adjust the pitch to achieve the appropriate frequency, loosen the sound adjustment screw while blowing from the air inlet, and turn the adjustment lever to set the optimal pitch. Turn the adjustment lever and tighten the sonic adjustment screw. This dog whistle can be used for any breed of dog. Like all silent whistles, this professional dog whistle makes a considerable noise. To some people, it sounds like air escaping, like blowing through a straw. Others have heard a very faint hiss, like a teapot starting to boil. This is a great way to hear your voice while you train your dog and teach them obedience. When your dog does this correctly, give him treats and make your dog a listening and obedient friend.Good quality product