Everything you need in one rackmount unit. Gem Sound's CMP-500 is a Dual CD MP3 USB Player & music mixer in a single rackmount unit and packed with performance features. It combines a Gemsound DJ mixer with a dual CD player. Features include Rotary tone controls ( high / mid / low ), CD, Mic and line inputs, headphone jack, Loop and reloop ( in & out ), 2 Channel RCA master output, 2 channel REC output, Photo Interrupter jog wheel and CUE on /off switch for each channel. Simply plug this unit into your home stereo or a set of powered speakers and your complete system is ready to go.