fixed HDD tray,USB flash driver back up, audio 
H.264 real-time high compression, support dual stream network transmission
Stand-alone Linux2.6 operation system
Graphics & Windows OSD interface
Support D1, HD1 and CIF recording resolution
ADPCM audio compression
Support triplex operation: record, playback, net transmission
Support to operate with USB mouse
Support remote view with Mobile Phone
Support to backup & upgrade with USB flash disk
Support to real-time remote view with IE (Internet Explorer)
Support to transmit audio via network
Support PTZ control via built-in RS-485 port
Selectable packing time for recording files
Optional VGA output