-H.264 realtime network DVR; -USB,PTZ,Audio,Network, Alarm; -Phone surveillance,CMS, Audio; -Dual stream technology 4 Channel DVR Recorder H.264 H.264 compression ... , network transmission and backup in the same time.Remote control DVR to monitor and playback, remote control the cradle head and ... the product will be free from maintenance within warranty period. 4 Channel H.264 Car Mobile DVR Recorder