The Numark CDN77USB Professional Dual USB & MP3 CD Player mounts into a standard 19" rack and is a flexible solution for both CD and MP3 DJs. The CDN77USB features dual CD decks and dual USB inputs for connecting external USB hard drives. Assign MP3 files to either deck, from either drive, and enjoy the flexibility of MP3 title display on the large LED displays. Additional features include scratching, seamless looping and variable 4, 8, 16, 100% pitch control. The Numark CDN77USB is ideal for mobile DJs, venue installations, dance studios, home use and more.