The BOYA BY-BM3051S is an upgraded super-cardioid shotgun microphone, specially designed for DSLR, compact camcorders, audio recorders and more. Unique Capsule Captures Natural and Crystal-clear Sounds Featuring a unique custom capsule, it captures natural sounds in the 20Hz to 20kH. And the improved sensitivity and signal to noise ratio make sound clearer. Super-cardioid Microphone with Stereo and Mono Recording Modes Featuring a super-cardioid polar pattern, the BY-BM3051S does really highlight the forward sound source. And it also supports switching from Stereo/Mono modes, to meet your recording demands in different scenarios. Automatic Power ON-OFF Function Offers More Convenience When switch to “AUTO”, the unique power ON/OFF can allow the BY-BM3051S to be consistent with the on-off state of the camera. Multi-function buttons for Precise Adjustment The BY-BM3051S also gives users more convenience with different buttons. For example, two-step high-pass filter and a three-position level control buttons help you to adjust the output precisely. And the built-in amplifier allows you to monitor the audio in real time via the 3.5mm headphone output. And powered by two AA batteries, the BY-BM3051S can be used for more than 60 hours.