These ingenious cables allow you to bypass the need to use your interface to pass normal vinyl records. With 1 simple XLR click you can easily connect your Serato, Torq, and of course your Traktor Scratch box into the mix. You need two per system (one replacement cable for each turntable/cd player setup). These will be the club standard as far as ease of use plugging a variety of DJs into the mix so if you're not using the cables and your club doesn't yet have them installed make sure they order two of them so it will be easy for all the top talent to come in and set up in literally seconds.