Silver plated nickel. Insert in the mouth and manipulate with the tongue. Produces a widely varying and easy controlled range of pitches popular at sheep dog trials.
Sometimes called the Shepherd’s Lip Whistle made famous by the television program, One Man and His Dog. This professional model enables the dog trainer to create a crescendo of sound in tremendous variety.
There are many dog trainers who consider this to be the ultimate in-tune communication with your dog.