Simple and dependable – You’re gonna love the way this call works. The Sonic Dome™ Series has been designed so the call is automatically positioned correctly in your mouth. The dome gives you a consistent distance between the reeds and the roof of the dome, for an incredibly consistent sound. The Sonic Dome™ Series calls use latex reeds. These calls will do it all. Features: Two Latex Reeds. Reproduces Estrus™ cow and heard bulls sounds.