Great way to get audio, especially for on-the go surveillance. Micrphone has built in audio and 3ft power/video cable attach to microphone. Microphone hear great up to 50ft range. The distance of audio will varies on tone of voice. We recommend you stay within a specific range to get clear audio. The closer you're around the mic the louder you can hear. Works great with any portable dvr. Plug power to any 12v battery or 12v wall power adapter and plug audio connection to audio recorder. Include Power adapter.