[Professional Dog Whistle]:Dog Whistle Training, It is easy to operate, you can loosen the sound adjustment screw, and then turn the adjustment lever to obtain the desired ultrasonic frequency. Pay attention to your dog's response to each setting until your dog shows the strongest response. This is a dog whistle that can quickly stop barking. It can help you teach dog obedience and learn basic skills. [Adjusable Frequencies]: Different respond to different frequencies. Our dog training whistle has a nut and screw that would adjust the frequency when turned. Notice your dog's reaction to each setting until your dog exhibits the strongest reaction [Absolutely Safe]: The dog whistles is made of copper + nylon. Ultrasound frequencies attract the attention of without damaging their hearing and without any health problems. [Remote ]: Ultrasound can travel up to 1000 meters. After training, even if the dog is not in your field of vision, the dog can make corresponding actions (Sit, , Lay Down, Up, Heal) according to your whistle. At any time use dog whistle to make come to you, no need to shout [Suitable for All ]: Silent dog whistle suitable for all dog breeds including (Labrador, Scottish, Golden Retriever, German Shepherd, Beagle). You can get in touch with your dog anytime Color: Black & White Material: copper + nylon Package Contents: 2 x Dog Whistle 2 x rope Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.