The Sony ECM-B1M is an ultra-compact camera-mount digital shotgun microphone designed for mobile video creators working with Sony cameras equipped with the Multi Interface Shoe. Released alongside the a7R IV, which benefits from its built-in Digital Audio Interface, the ECM-B1M is able to produce its best quality by delivering a digital audio stream directly to the camera through the Multi Interface Shoe. Other Sony cameras with the standard Multi Interface Shoe can still make use of the microphone as there is a selectable digital/analog output.