This dog whistle will help you control your dog's 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 a great tool to promote effective bark control. Professional Dog Whistle: You can adjust the pitch to get the right frequencies. Loosen the sonic adjustment screw while blowing air from the air inlet, and turn the adjustment lever to set the optimal pitch. Once the adjustment lever is turned, tighten the sonic adjustment screw. This dog whistle can be used on any breed of dog. Like all silent whistles, this professional dog whistle makes a little noise. For some, it sounds like air escaping, as if you were blowing through a straw. Others have heard a very faint hissing sound, like when a teapot starts to boil. This is a great way to hear your dog while you train him and teach him obedience. When your dog does it correctly, give him a snack reward, approach to make your dog a listening and obedient friend. Anti-lost Design: Our dog training whistles come with a high-quality lanyard and a special locking nut and cover, it allows you to carry this whistle anywhere without worrying about losing them. Product Name: Pet Whistle. Product Material: Metal. Product Size: 0.9 x 8.0 cm. Product Weight: 15 g/piece. Color: Black. Delivery Quantity: 2 pieces.