The Rocky Mountain Hunting Calls Yipper Yapper mouthpiece features narrow reed, plastic barrel, the tone cap and automatic Lip Positioner. Place fingers over the holes while blowing. This will change the pitch to a deeper sound and less volume. Remove fingers from the holes and the pitch will be higher with more volume. Makes a variety of prey sounds, juvenile barks and howls including baby jack, baby cottontail, distressed fawn, distressed canine and rodent squeaks.