These tri-cones have 3 small resonator cones in them. They have more of a typical Spanish style guitar sound. They are also a hell of a lot more expensive because even in the Depression when they were made they were expensive so demand was limited. Finding round neck versions of these is always hard. My hard core National contacts say that the Style 1, like this one that is plain (no engraving) seem to sound the best for some strange reason.