Features:1.Great as a training aid, Humans can"t hear the Ultra Sonic sound, but dogs can2.Also produces a sound that humans can hear, so that you know it works3.Adjustable pitch4.Copper/chrome plated finish5.New in the PackageSpecifications:1.Weight:0.88oz/25gPackage includes:1 x Dog Training Whistle UltraSonic Sound Ultra Sonic