KMX 02 by Numark,The only all inclusive karaoke and mobile disco system of its kind, the Numark KMX02 features dual CD+G drives with an integrated mixer and is the perfect all-in-one solution for DJs and clubs to add Karaoke to their entertainment mix. Offering three microphone inputs with tone control, two switch controlled composite video outputs for graphics, and ± 12% pitch control with a pitch bend wheel among its key attributes, the Numark KMX02 is ideal for mixing Karaoke CD+G and regular audio CDs, The Numark KMX02 has a key change knob to adjust the musical key in half steps without changing the speed. Key change is very useful for karaoke DJs by allowing you to adjust the key of the song to accommodate the vocal range of the karaoke performer. Rotating the knob to the left will result in a lower key (flat), while rotating to the right will result in a higher key (sharp).