Description A call designed to give the caller the option of bugling very aggressively or very passively. It also cow calls very well. #C2 The âSlotted Dome TSTâ 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 âSlotted Domeâ upwards to the roof of your mouth, latex down and open end of the diaphragm towards the front of your mouth.