8-Channel Real Time Operating System Playback Resolution: CIF (352?88) Advanced MPEG-4 Compression Algorithm Secure and Reliable Embedded RTOS Operation System Stable Video & Audio Synchronization Advanced Potential HDD Capacity Expansion User-friendly Graphic Menu Interface Advanced File Management System with Full Intellectual Right Independent Hardware Compression for Each Channel Backup via CD/DVD-RW, USB and Network Standby Mode for Non-working HDDs Multi-recording Mode (Manual, Schedule, Alarm and Motion Detection) Channel Image Circle Cruise Function Full Remote System Access, Monitoring, Playback, Configuration, Searching and Backup through Network 3-Level Authorization-based User Management System