ITEM NAME:Dog Puppy Pet Whistle Ultrasonic Adjustable Sound Key Chain Training.This Whistle can help you to train your dogs.Using this product can produce ultrasound and spread very far. Within3km can be heard. Dog whistle will send a dog can detect ultrasound. Dog whistle can be issued in addition to the human voice can be heard outside the tube, while the sound people hear is, only dogs can hear frequencies, this frequency ultrasound transmission is very far, so the dog can be very far away hear the sound.
