The MXL FR-400M boundary microphone has a wide cardioid pickup pattern that is effective at recording stage performances and concerts. Record and share a performance with family and friends. Capture a live concert to turn into a cd or the soundtrack to a video. The FR-400M offers many options. For example, it can be placed under the lid of a piano. It has a built in switch to boost or cut low frequencies by 6 dB for a more balanced frequency response.