Product Name ：Prefix Plus-T Onboard Preamp Matrix Pickup EQ Tuner Soft Piezo Pickup Equalizer System Model ：Prefix Plus-T Scope of use ：For all Acoustic Guitar Include / Set : 1* Prefix Plus-T The Prefix Plus-T features ultra-quiet electronics and Volume, Bass, Treble and semi-parametric Contour controls. The Prefix Plus-T also offers a Brilliance control, Phase switch and Notch filter to help fight feedback. In addition, the built-in chromatic tuner can be used without plugging in the guitar.