The Phelps AMP Maverick Diaphragm Elk Call has been specifically designed for the most authentic bugles, and realistic cow calls to meet the demands of World Elk Calling Champion Dirk Durham. The latex in this reed is stretched tight to an optimum point which allows the call will settle in for the longest possible duration of calling perfection. With this in mind, after 20+ hard bugles, the reed will begin settling in and continue to sound better and better. FeaturesLatex thickness between intermediate (0.004") and advanced (0.005")Designed to imitate an old cow or a herd bullHigh and powerful volume that requires additional air pressure