Electro-Harmonix White Finger XO Analog Optical Compressor<div style="text-align: left;"><strong>[Product Information]</strong><ul><li><span class="a-list-item"> LED optocoupler for a faster attack compression </span></li><li><span class="a-list-item"> Lamp optocoupler for softer blooming compressor </span></li><li><span class="a-list-item"> Quiet long sustains with transparent tones </span></li><li><span class="a-list-item"> Pre-gain control lets you control how hard your instrument hits the compressor </span></li><li><span class="a-list-item"> 40DC-100 power supply included </span></li></ul></div><img src="http://ecx.images-amazon.com/images/I/51oBkziAZTL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/51x%2BSgtqkhS.png" noproxy>