H.264 compression    4ch Video input, 2ch Video output; 4ch Audio input, and 1ch Audio output,4ch alarm input, and 1ch alarm output. Two USB interface, USB2.0 for data backup, USB1.1 for mouse operation.
3.5” SATA HDD. Video standard：PAL，25f/s，CCIR625line，50scene；NTSC，30f/s，CCIR525line，60scene；Video code rate：CIF: 256Kbps ~ 1.5Mbps，8leavel optional，１is highest，8 is lowest；HD1: 600Kbps ~ 2.5Mbps，8 leavel optional，1 is highest，8 is lowest.Special file system for secureity.
16 nature translucence GUI, note for menu selected
optimized four channel simultaneously playback, (8ch just support one channel playback)
double level user management
Support the live view, parameter setting and copy playback video via network.