Rich N Tone Mondo S Steel Shot/Black Duck Call - Introducing the Mondo S, the "S" stands for "Shorty" we've shortened the regular Mondo barrel a strong three quarters of an inch offering the regular Mondo in a new short barreled version. This speeds the air up getting to the reed and effectively reduces the back-pressure even more, what you put in, is what you get out along with making it a touch higher pitched... Clean on top and a higher pitched rattle in the middle just may be the key that unlocks a Mondo wad of Mallards high out of a silver blue winters sky. Shortened Regular Mondo Barrel Effectively Reduces Back-Pressure