【4K Ultra High Definition and Color Night Vision】This ultra HD 4K CMOS image sensor allows the camera to capture more light,which improves color,contrast,and low-light performance. Up to 100ft night vision and with advanced starlight sensors can see brighter full-color nighttime videos, providing users with crystal-clear footage during day and night. 【Face/Person/Vehicle Detection & Smart Alerts】Our AI-powered detection feature intelligently identifies faces, people, vehicles, or other objects, reducing unnecessary notifications. You will receive instant App push notifications, email alerts and sound alarms (siren) when motion events are detected. 【Two Way Audio & Remote Access】Built-in mic and speaker let you stay in touch with your household. Check in with the family or tell your dog to stop barking, or say hello to the delivery man through the free App. And you can live view & playback on mobile phone anywhere anytime. 【4K 16-Channel NVR Upgrade to 24CH Expandable】Upgrade your 4K 16 channel NVR to a 24-channel system with our expandable solution. Simply add a PoE switch (not included) and you can expand your system to support up to 24 PoE cameras. This gives you the flexibility to add additional cameras according to your needs. You can integrate more (ZOSI only) 8MP, 5MP, 4MP, 3MP, or 2MP PoE cameras to enhance your surveillance. 【Dual-Disk Backup for 24/7 Recording】Our dual hard drive design supports extended continuous recording and USB backup. It can accommodate up to two 6TB hard drives (not included). With a built-in 4TB secure-grade hard drive, you can rely on it for reliable all-day recording. The NVR can be set to automatically overwrite the oldest stored footage or transfer these video files to a USB thumb drive or external hard drive via USB.