Not too long ago, little was known about deer vocalization, but research has proven them to have over 14 different vocalizations. Primos has developed calling devices and techniques that make the calls and sounds most beneficial to the hunter. Primos deer calls are compact, convenient, and they sound like the real thing. The Magnum Trophy Grunter has a fully adjustable reed assembly to produce 6 calls-from throated buck grunts to lovesick doe bleats. Effective on whitetails, mulies, blacktails and coues deer.