4 Band Guitar Eq Acoustic Guitar Pre-amp W/transducer Piezo-840 Slim Type-365# 100% brand new and unused 4 band eq with lcd tuner,Input impendence:10ohm,Frequence responsce:20HZ-20KHZ ass: +-12dB at80HZ ,Midd: +- 12dB at 800KHZ ,Treble: +- 12dB at3KHZ Phase reverse switch, Blanded and unblanced output jack, Power supply(9v battery not inlcuded) size: length9.4cm* width4.4cm*height3.8cm