1.Support 1pcs HDD and 2pcs SD card.if HDD with problem,it will change to recorder in SD card automatically. 2.Support 1ch audio, 4ch input and 1ch output, 1ch CVBS ,video output(ADPCM),voice and image synchronously recording 4CHS MDVR System include following Part : 4CHS DVR MS-580 7" TFT monitor MS-708 4pcs CCD cameras. MS-750/MS-770/MS-780 Extension Cables for camera 500GB HDD(extra part ) 64GB SD Card (extra part) HDD Data Transfer box (only choose GPS function ,necessary part) Remote , Power cable & Disc for free part. Weight : 8.5KG.