Primos Sentry Cow Reed - The "Sound Plate" automatically positions the call in your mouth at the right place and angle, making calling elk easier. The Sentry Plate Single has a"'Sound Plate" set at 16 degrees, which is perfect for cow, calf talk and spike bull bugles. The angle of this sound plate is set at 16 degreesThis single-reed call is prefect for cow, calf, and spike bull sounds without switching calls