The inhale-only feature makes this call 100% freeze proof, which allows you to hunt trophy bucks in extremely cold weather. This is a double reed call that adjusts from Estrus™ Bleats (with the push of a button) to throaty buck grunts. Also, knowing your direction and which way the wind is moving is critical to a successful hunt, that is why we have provided a built-in compass. Features FREEZEPROOF: Inhale-only operation keeps moisture away from the reeds ACCURATE: One-of-a-kind double-reed provides realistic deer grunts and aggressive clicking tones of dominant bucks Perfect for both long-range and close-in calling ADJUSTABLE: From Estrus™ Bleats to throaty buck grunts Includes built-in compass