SILENT DOG WHISTLE
The Acme Silent Dog Training Whistle provides an extremely high pitched, adjustable sound that dogs can hear--and that is almost inaudible to humans. Developed for hunting dogs, the training whistle can be heard by dogs from up to 400 yards away (direction and strength of wind may affect the distance). This precision whistle allows you to set the ideal pitch with a pitch register. Instructions come included on the back of the package.