The Sony ECM-W1M Wireless Microphone is designed specifically for Sony cameras and camcorders that feature the proprietary Multi-Interface Shoe. The microphone comprises two components: a transmitter and a receiver.  With the receiver attached to your camera, it is still possible to capture additional audio using the camera's built-in microphone. In addition, audio picked up by the camera can be relayed back to the transmitter. There is also a headphone jack on the receiver so that the camera operator can monitor audio even if the camera itself doesn't provide a headphone of its own. Finally, the transmitter features a 3.5mm mic input allowing you to use a third-party microphone rather than the built-in one. Includes windscreen to help reduce wind noise when filming outdoors.Transmitter powers from a single AAA battery; the receiver power directly from the camera