It's a complete pedal for your bass. Look at this brief description and you'll realize that you can't live without this pedal:
2 channels (Clean and Drive) that can be changed in a single step;
Independent Bass, Mid and Treble control;
Volume controls for each channel, so you can set each channel with its gain;
3-position treble adjustment switch for the Drive channel;
The Drive channel also has a Drive addition control in addition to the volume control.;
P10 Input and Output, but if you need to plug it directly into the desk or audio interface you can use the Balanced XLR output;
Ground Lift button to eliminate squeaking.