This classic undersaddle pickup from Freshman is made for 12 string and classical acoustic guitars. The AGX-312 is suitable for most classical or 12-string guitars with 1/8″ (3.2mm) saddle width and 2.312″ E to E string spacing. This is Fishmans classic Undersaddle ceramic guitar pickup. AG-Series pickups like this do not require a battery but an impedance-matching preamp is recommended for best performance. This pickup has a 1/8? (3.2mm) saddle width and 2.312? E to E string spacing. To read more about the AG Pickup Series please download the user guide below. Alternatively to learn more about the installation process please download the following PDF.