BeAPet Ultrasonic Dog Training Whistle &ndash; Stainless Steel Smooth Finish Bullet Shape Pet Pigeon Whistle With Holster &ndash; 23 To 54 kHz Frequency Range Undetectable To Human Hearing &ndash; Safe, Non-Toxic, And Animal Friendly &ndash; Suitable For Home And Camp Pet Training &ndash; Audible To Pet Dogs Even In Long Distance &ndash; 2.5 Inches Long x 0.375 Inch Diameter - Best Gift and Accessory Kit for Pet Lover Exquisitely crafted leather and durable steel product materials: pure copper body, 304 stainless steel rivets, high-grade PU leather and lobster clasp for necklace or lanyard attachment Ultrasonic high-frequency range designed for dog hearing but can also be used for training eagles and pigeon call Use to effectively discipline, command, train, and interact with pets to inculcate good behavior and develop helpful skills Produces sound that is audible to dogs yet soft to the human ear; easily catches your dogs attention but doesnt sound annoying to the human ear