Up to 4 cameras with 1080p realtime preview. H.264 dual-stream video compression. All channel 960H realtime recording. HDMI/VGA/TV simultaneous video output. Support A/D switch. 4 channel synchronous realtime playback, GRID interface & smart search. 3D intelligent positioning with Dahua PTZ dome camera. Support 1 SATA HDD up to 4TB, 2 USB2.0. Multiple network monitoring: Web viewer, CMS(DSS/Smart PSS)&Smart Phone(DMSS).