Aguilar OBP-3SK Onboard Bass Preamp

3-band EQ with 18dB of boost/cut at 40Hz, 400 or 800Hz (selectable by toggle switch, and 6.5kHz, can be installed as 9 or 18 volt circuit, 1" x 1" x .6", Includes stacked treble/bass pot, midrange pot and toggle switch for midrange frequency selection.