Acme Silent Dog Whistle Silver, adjustable

Amazon.com Instructions on back of package. Acme Silent Dog Whistle from Markwort 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. Features: High pitch can be heard by dogs not people 400 yard range depending on conditions Pitch register for easy adjustments Measures four inches long Product Description Designed and made in the UK, brass nickel Plated 'Silent dog whistle', adjustable frequency, protective end cap.. Brass nickel plated 'silent dog whistle'