... : live, record, playback, backup, network transmission, mobile phone surveillance4. Support backup with USB Flash Disk, Movable ... 4CHDigital Zoom,PIPSupportsMultiplex OperationLive\display\Playback\Recording\Backup\Mobile phone Surveillance \Network simultaneouslyDisplay ResolutionPAL:D1(704* ... (One software for at most 100 DVRs ),Free supply to useDual StreamSupport(Main and secondary interchange ...