RedBone builds two snow goose calls. Each one supports a different style of calling. The "Snow Goose Call" is the higher pitched set up. Its used for aggressive calling over large spreads on "dry ground". The other one is the "Buzzerd". Its set up for the less aggressive and more realistic calling associated with smaller mixed spreads where white is not the dominate color. Its an excellent small flock and single call and is effective over water.
The Buzzerd set also supports canada calling which can come in pretty handy if you're in a white spread and some canadas show up. This file is the Buzzerd doing non aggressive snow and canada sounds.