The 8-Channel DVR from Dahua Technology supports HD-CVI, analog, and IP video inputs for use with a variety of systems. The DVR uses H.264 dual-stream compression technology for fast, high-quality data streaming, and it features an 8TB HDD capacity (hdd not included) which allows you to store high-definition recordings in real-time. Four RCA inputs and one RCA output provides 2-way audio, and HDMI and VGA interfaces enable simultaneous HD video output. The RS485 interface offers PTZ control, and two USB 2.0 ports allow you to transfer recordings to external storage. Live viewing can be remotely accessed using an iOS or Android smartphone or tablet for on-the-go surveillance. ONVIF-compliance offers compatibility with a wide range of cameras and other devices.