suitable for long distancesindividually tuneableOperating Range up to 200mGreat for training your dogDogs mainly react to tones and acoustical signals but not to speech.They learn easier when the tones and acoustical signals are the same.The High frequency Whistle is perfect for the dog's education.Dogs perceive high frequency whistles because they have a wider audio frequency range.The pitch can be set by adjusting the set screw located under the plastic cap.Silent Whistles made of metal are available with and without frequency protection.Dogs hear in a different frequency range to human beings.You can profit from this when you use whistles with sounds in such a high frequency range that humans do not hear or almost do not hear the whistling.The constant frequency (individually adjustable with the frequency protection) guarantees that your dog gets clearly transmitted orders.Variations in your voice (e.g.nervous vibrations) which could confuse your dog are avoided that way.At the same time you prevent any people nearby becoming annoyed by loud noises.Details: metal- with frequency protection- individually tunable - avoids disturbances - with ring for fixing a cordTip: The best training results are achieved when dog and master are having fun during the training and feel experiences of success.A ground rule is: Correct behaviour has to be rewarded and consequently repeatedPackaging: 2x dog training whistleOnly the above package content, other products are not included.Note:Light and different displays may cause the color of the item in the picture a little different from the real thing.The measurement allowed error is +/- 1-3cm.