The FR-400 from MXL is a boundary microphone. This kind of microphone is designed to rest on a flat surface (or be attached to a wall) and to capture the reflections of sound that bounce off of the area around the mic. They're handy to use in live performances and video productions because of their unobtrusive low-profile design.
The three capsule array in the FR-400 results in pristine audio reproduction and a minimal noise floor. It sits on a theater's stage or a tabletop with minimal visibility. The low frequency boost switch can be used to boost or cut low frequencies by 6 dB in order to balance the frequency response. It requires phantom power to operate.