From MXR:

"Take your favorite studio compressor to the stage with the MXR Bass Compressor. A complete array of controls-Attack, Release, Ratio, Input, and Output-makes it easy to fine-tune your sound, from subtle peak limiting to hard squashed compression effects. Its CHT™ Constant Headroom Technology gives you plenty of headroom and clear performance. This totally transparent compressor allows your full dynamic range to shine through until your signal reaches the compression threshold, which is indicated by the ten, highly visible gain-reduction status LEDs. It's all packed into a durable, lightweight aluminum-housing pedal that's the size of a Phase 90."