SOUND RECORDING AND 24x7 NVR RECORDING: The Reolink IP Cameras can record videos with sound 24x7, then transmit HD recordings to Reolink PoE network video recorders. This NVR supports up to 16 cameras recording simultaneously to the built-in 4TB HDD. For more space, an extra 6TB HDD can be added. FREE VERSATILE APPS AND REMOTE VIEW: Explore rich features and functions in free Reolink App/Client and download it from iOS or Android, Windows or Mac without monthly fees. Intuitive and easy-navigated software ensures local/remote access to your property. Enjoy peace of mind anytime, anywhere. FULL INTEGRATION WITH SMART REOLINK CAMS: The Reolink PoE NVRs can integrate human/vehicle detection & playback from Reolink IP cams to build an intelligent system. By adding more Reolink cameras with optical zoom, auto-tracking, two-way talk, motion-triggered spotlights features, you can even build a cutting-edge home security system on your own. PoE, EASY SETUP WITH PLUG & PLAY: PoE with only one Ethernet cable (up to 330ft) for Reolink PoE Cameras to transmit both power and data. You can live view and access the cameras with or without the internet as Reolink PoE NVR can make an independently running system itself with the DHCP function. ONLY WORK WITH REOLINK IP CAMERAS: Work perfectly with all Reolink PoE 4K/5MP/4MP cameras and Reolink WiFi cameras with DC power (battery-powered cam not included), such as RLC-510A, 520A, 811A,810A, 820A, 823A, 842A, Duo 2 PoE, Doorbell PoE, E1 Outdoor cameras. Manage up to 16 Reolink cameras simultaneously easily.