The M40 is a bold new direction for microphones incorporating integrated circuit technology. The M40 has been designed for piano but works equally well in other applications such as boundary layer micing (conference, stage). Once again, the AMT product line stays consistant with the most natural sounding piano microphone system on the market. Mono in design, the system allows for use with the piano lid closed. It is the only system on the market that will allow that. It is capable of picking up subtle passages as well as sound pressure levels up to 141dB. Its rugged construction of anodized aviation aluminum allows it to withstand high impact while being lightweight and non-corrosive. The M40′s signal can be split and frequencies rolled off in a specific way to create a stereo image. The M40 comes with the AP40 aluminum pre-amp with chip technology, which can be powered by phantom power or 9 volt battery. Also comes with hard shell case.