DJR400 is a very new concept of "travel" mixer, the idea is to be able to carry it with you anywhere , very easy to plug with it's back connections , it includes all the specifications of the DJR100D in a 4 lines portable mixer ! You don't have to « rack » it or do a long soundcheck you can just plug it in a system and play , controling the room's system with the very powerfull integrated cross over.