Network Video Recorders (NVRs) from Q-See feature a variety of ports. They allow you to make crucial connections; from your cameras to the NVR, and from your NVR to a nearby monitor. Some models may also feature a port for a mouse, to facilitate system setup and control. Your unit may also feature input/output ports for audio, and a port to connect your unit to the appropriate power source (either 12V DC current, or 120 V standard AC current). Other options may include USB port(s), for external storage device backup, and/or a mouse, and an ethernet port to support a local area network (LAN). More sophisticated units may also feature ports for external motion-detection sensors, PTZ camera(s), and various alarms.