The MXR M76 Studio Compressor Guitar Pedal is a True Bypass Classic Studio Compressor Pedal in Phase 90 size format. It features attack, release, ratio, input, and output controls, and fine-tune the compression level thanks to the bright visual feedback meter on the stage. Constant headroom technology ensures the load of the headroom for clear, dynamic performance. Main features of MXR M76 Studio Compressor Guitar Pedals are: Lightweight Aluminum Housing True Bypass Control: Attack, Release, Ratio, Input & Output Bright & Clear LED Gain Reduction Statator Constant Headroom Technology