Rocky Mountain Elk101 Contender Elk Call - The Slotted Dome TST elk diaphragm call is designed to be placed further forward in your mouth, behind your front teeth, this helps to prevent gagging and gives you easier control of the latex. To operate the call, place the Slotted Dome upwards to the roof of your mouth, latex down and open end of the diaphragm towards the front of your mouth. Create Bugles or Cow CallsTone Top Diaphragm CallIntermediate Call