... RJ45,RS232,RS485 interface 8pcs SATA hard disks 4-CH Network Video Record For IP Camera ModelYW904NCVideo compressionH.264Video SignalPAL/NTSCVideo ... , No HDD notification, HDD lost alarmAlarm LinkageBuzzer, Snapshot and video recording, email notification, External Alarm outputAlarm input16 channels inputAlarm ... 185 1 pc/boxNet weight7.1kg(Without HDDs) 4-CH 1080P Network Video Record For IP Camera