The Stretchback Grunt Call has adjustable sound allowing you to instantly change your call by extending the rubber flex tube. This allows you to sound like a small buck, a big buck or a moving buck. It also allows you to make all types of buck grunts. The rubber flex tube (not plastic) is made out of a special rubber that not only produces the robust, most realistic call sounds but is also perfectly grunts when you extend or contract the call. It aslo features Dual Chamber Technology™ and a Freeze- Free design - there’s nothing worse than a call that freezes up when you need it most!