Simple to use. Lets you play louder and sound better!  With TWO unique proprietary surgically narrow fixed depth sweepable filters and phase inversion the Feedback Master has everything you need to easily control feedback without ruining your sound.  The circuitry is 100% analog, pure class A and all discrete for pure sweet sound and is the best sounding feedback suppression method available. The Feedback Master will work with virtually any pickup, active OR passive. The Feedback Master comes with both a belt clip and a microphone stand adapter. R$275