GEB-7 Bass Equalizer

50Hz to 10kHz frequency range specifically designed for bass
Full range response, even for five- and six-string basses
Can be used as a "boost" or "cut" pedal using the level control knob
Great for eletric-acoustic bass applications
AC adaptor or 9V battery operation
BOSS five-year warranty

https://www.boss.info/us/products/geb-7/