This Network Video Recorder uses wireless cameras to save you from running video wires through the home or office. You just need a power outlet close enough to the camera to plug in the individual 12v power supplies with 13m long cables. Perfect for situations where access through the building is difficult such as old double brick houses or apartments. The kit includes four wireless 4K Bullet cameras with a transmission range up to 40m. Each camera has built-in infrared LEDs for night vision up to 12m and Thermal Detect Technology to help prevent false triggers. Built-in microphone and external speaker can achieve two-way call between cameras and APP. The NVR includes a built-in 1TB HDD and supports FTP storage or Dropbox Cloud Storage to safeguard your data and push notifications to send alerts to your phone. Watch live or playback video on your HDTV or LCD monitor via HDMI or VGA or log in remotely via your Apple or Android compatible Smartphone or Tablet using the free app. Connecting your Smartphone is made easy using Peer-to-Peer (P2P) technology and scanning a QR code with the app. A USB mouse is included to navigate the on-screen menus. A second USB 2.0 port and a micro SD card slot allow you to backup data to external storage.