Freeze Proof Open Reed Moose Calling PowerThe Primos Moose Horn Black 12 Inch is an open reed call with a unique hose in horn design that automatically reproduces deep guttural moans of rutting cows in estrus. Built 100 percent freeze proof for cold conditions. 12 inch open reed design 100 percent freeze proof Hose in horn construction Produces deep cow moans Ideal for rut season