... Multiplex operation: live, record, playback, backup, network transmission, mobile phone surveillance. DVR Support backup with USB Flash Disk, Movable hard discus writer ... production line contains: 4/8/16 channels 3G Stand Alone DVR, H.264 DVR, CIF DVR, D1 DVR, Combo DVR, DVR Kits 8CH H.264 Compression surveillance DVR