Fishman PRO EQ II Acoustic Guitar Preamp..... New look and updated circuits! This perennial favorite now features a new injection-molded case, an input trim control, advanced new electronics, and longer battery life. 4 main controls include bass, middle, treble, and brilliance, plus a phase switch to help control feedback. The Pro EQ II Preamplifier can be used with any type of piezo or magnetic pickup. With improved features, this Fishman preamp won"t let you down!