4-Channel Video Standalone DVR,H.264 compression,Supports Real-time,Net ... /s), NTSC (525Line,60f/s)Video Input4 Channel, BNC,1.0V p-p/75 ohm Video Output2 ... p-p/75 ohm,VGA x 1Audio Input4 Channel, RCAAudio Output2 Channel, RCA x 1, Bidirectional talk x 1Alarm ... Input4 Channel, Trigger closed without Voltage,Open or ClosedAlarm Output2 Channel, Trigger closed without Voltage, ...