The CCTV-02 audio surveillance microphone from CCTV Camera Pros can be used as an add-on mic for any security camera. On our test bench we have a 25 foot premade siamese coax cable which is typically used for CCTV cameras, a 300ma DC power transformer, two BNC to RCA converters, and the CCTV-02 microphone. First, I connect one of the BNC to RCA converters to the plug and play cable which allows me to connect to the RCA out of the microphone. I also connect the power input of the Mic to our premade cable. On the other end of the cable, I connect the power portion of the cable to the DC power supply that is included with the Mic. Depending on the audio input type of your DVR, you can use the native BNC connection of the cable or use the other converter is your DVR uses RCA input for audio. Because the CCTV-02 mic uses its own cable and power supply, it is able to work as a stand alone surveillance microphone or it gives installers the flexibility to use in conjunction with a camera but not neccessarily have to mount the mic near the camera. CCTV Camera Pros has carried this Microphone for several years and has found the quality of it to be high. Our customers have this microphone very useful for indoor surveillance applications and outdoor applications where the mic is not directly exposed to rain. For addition information and pricing, please visit www.cctvcamerapros.com/Audio-Surveillance-Microphone-p/mic-cctv-02.htm. Thank You for watching.