The ZA12 Transcription Arm is an effort to take the strengths of the SA1.2, already recognized as a Class A component, and marry them to a purist approach. This meant giving up detachable headshells and lengthening the arm for lower tracking error. While the ZA12 is 3″ longer than the SA1.2, the total mass of the ZA12 is lower, guaranteeing that the new arm will be compatible with the broadest range of high quality cartridges. And if you want more mass for very low compliance cartridges, you can easily add it.