These friction calls incorporate an integral acoustically designed sound chamber that lets the call function as if it were a finely tuned musical instrument. Most friction calls only play well close to the edge and seem to get dead in the middle. Not this one! We wanted you to be able to use the entire surface of the call. The angled inside edges allows each yelp, cut, cackle, cluck and purr to vibrate crisply down the walls and out the new “Tri-Flow” sound slots from the edges or the center of the call. Whether it’s the “Hen Under Glass” or the “Straight Slate”, each call is guaranteed to be of the highest grade production friction call that money can buy. Each call includes purple heart striker. Lifetime guarantee!