Thanks to its unique port-hole design, the Illusion Snow/Blue Goose call is extremely versatile! Easily mimic all of the sounds of Snow and Blue Geese. By simply covering or uncovering the sound hole with your fingertip, you"ll be able to generate the wide variety of sounds necessary to sound like an entire flock of Snow Geese. This "flock effect" is crucial to being able to call in Snows and Blues.* The Snow/Blue Goose call also includes Illusion"s "Don"t just call, communicate" instructional.