The Acme Plastic Dog Whistle 212 is Medium Pitch, a great all-rounder with a sound that is well within human hearing. This special whistle holds its frequency no matter how loud you blow. Your dog will always know it’s their whistle. Known as the Pro-Trialler, less confusing for your dog especially over distance or if you blow hard when your dog becomes disobedient or goes off course during a Trial. This whistle is especially good over distance and works very well with Pointers, Setters, Retrievers, Labradors, and most Terriers. An excellent whistle for harder to train dogs and heavy cover situations.