Seymour Duncan 11900-007 Studio Bass Compressor Pedal w/ 2 Patch Cables Compression Ratio: Soft-knee, adjustable from 1:1 to &gt; 20:1 Maximum Compressor Gain: +33dB Attack Speed: Adjustable from 8ms to 27ms Input Impedance: 1 Megohm Output Impedance: 2.75K ohms maximum