ETS - Hanging Directional Pre-Amp Microphone. High performance, Unidirectional preamplified microphone for high ceiling and high background noise applications. Flush mountPre-amplifier mounts on ceiling and microphone hangs 6-25\' down. Built in limiter circuit automatically lowers the output level during loud sound intervals. Selectable lo-cut and hi-cut filters significantly reduce background noise. Flexible plastic plate mounts flush or on a single gang electrical box.