The OBP-2SK was designed to give bassists fat tone while being small enough to fit into tight control cavities. Wire this preamp with one 9 volt battery and it will fit into just about any instrument. With +/-18dB of boost and cut at 40Hz and +/- 16dB of treble boost and cut at 6.5 kHz you can emphasize just the right frequencies to make your bass sound great in any mix.