The Power Mule Deer & Blacktail Grunter with built-in compass reproduces Throaty grunts and Estrus bleats with simple inhale-exhale operation. It is perfect for Mule Deer and Blacktail deer, especially during the rut. Features: - effective for long-range calling - dual-reed Assembly for inhale-exhale operation - reproduces Throaty grunts and Estrus bleats by simply inhaling and exhaling - Includes a built-in compass.