The smx-15 was engineered to be the ultimate video microphone with outstanding audio quality, appealing design, and all of the functional features one expects in a top-of-the-line, camera-mounted microphone. The smx-15 is a powered shotgun microphone that uses a super-cardioid polar pattern to focus on sound in front of the camera and is equipped with the same high-quality element as Azden's sgm-250 shotgun microphone to record broadcast quality sound. With a 20db gain booster, you can get a strong, clean audio signal into your camera, minimizing the need to turn up the camera's noisy preamp. Also included is a -10db pad to protect against distortion when recording in loud environments. The smx-15 has a wide frequency response ranging from 40hz to 20khz, so the audio you capture will sound full and natural. Additionally, a low-cut filter switch is included for reducing the level of low frequencies below 120hz, which is especially useful for mitigating noise caused by air conditioners, wind and traffic. The smx-15 is powered by two AA batteries for up to 24 hours of operation. The battery indicator LED light lets you know when its time to change batteries and you can maximize battery life by using the unique auto power setting. When set to auto, the smx-15 can detect when a camera is on and will automatically power on and off with the camera (requires a mic input that provides plug-in power). Integrated into the design of the smx-15 is a custom made, shock absorbing shoe mount to isolate the microphone from noise and a ¼-20 thread at the bottom for mounting to boom poles and other camera accessories.