Dahua 32Ch 1.5U 4HDD's 16PoE 4K&H.265 Pro Network Video Recorder (DHI-NVR5432-16P-4KS2E) - Main Processor: Industrial embedded micro-processor, Resolution: 12MP, 8MP, 6MP, 5MP, 4MP, 3MP, 1080p, 1.3MP, 720p, D1, and more, Access Channel: 32, Storage: Local HDD and network, External Port: Audio Input: 1 channel, RCA connector, Audio Output: 2 channels, RCA connector, which supports voice intercom output, HDD: 4 SATA III ports, up to 10 TB for a single HDD. The maximum HDD capacity varies with environment temperature, Alarm Input: 16 channels, Alarm Output: 6 channels, eSATA: 1 eSATA, RS-232: 1 channel, used to debug and pass through serial data, RS-485: 1 channel, used to control PTZ, and it supports multiple protocols, USB: 1 front USB 2.0 port, 2 rear USB 3.0 ports, HDMI: x2, VGA: x2, Network: 1 RJ-45 10/100/1000 Mbps self-adaptive Ethernet port, PoE: 16 ports (IEEE802.3af/at), 1-8 ports support ePoE&EoC, OS: Embedded Linux