Micro space saving design Simple, two-knob interface (Compression and Gain) for easy-to-dial in compression Bass guitar appropriate compression ratios and attack / release parameters that sound natural and musical Studio-quiet with no artifacts Inputs: One 1/4″ jack Outputs: One 1/4″ jack Gig-saver bypass (signal passes even if your battery dies) Power: Nine-volt DC Heavy Duty steel construction Optional: 9 volt power supply.