The C.503 is a professional dual CD player designed for mobile and club DJs. If you need features like scratching, seamless loop, hot cue points, Key Lock (Master Tempo) and anti-shock memory, this CD player has it all and more at a breakthrough price. Features Professional dual CD player with compact 2U rackmount controller. Anti-shock buffer eliminates embarrassing CD 'skips'. Versatile pitch control with adjustable range (+ / - 8, 16, 32, 100%) Independent pitch and tempo control via Key Lock and Key Shift functions 3 hot start/cue points for quick cueing and instant playback Seamless looping and onboard effects (Brake, Scratch, Filter) Automatic BPM detection with Tap key Handy auto-cue function, plus fader start and continuous/relay play Reads CD-R/RW discs S/PDIF digital output.