These extra 12" vinyl records each have a Serato exclusive and unique control signal which allows Scratch LIVE to track the motion of the record, simulating the same movement with digital audio. Due to Serato's proprietary control scheme, the result is a feel and sound indistinguishable from playing vinyl. As a producer and DJ, the track you finished today can be played on a real turntable tonight. You'll never have to cut a dubplate again!