... 75Ω,PreviewSupport 1 channel or synchronous 4 channels preview.Recording ResolutionSupport CIF,HD1,D1 resolution optional, maximum 2CH ... level , 4 is the lowest level.Recording Mode support timed recording, alarm recording, manual recording.AudioAudio InputMic or line in, up ... up to 4 channels alarm input.Alarm recording,include the recording within 15 seconds ahead of the alarm startingOutput2Ch ...