Shure KSM137/SL End-Address Cardioid Condenser Instrument Microphone Highly consistent cardioid polar pattern Ultra-thin, 2.5 micron, 24 karat gold-layered, low mass Mylar diaphragm for superior transient response Class A, discrete, transformerless preamplifier for transparency, extremely fast transient response, no crossover distortion, and minimal harmonic and intermodulation distortion Premium electronic components, including gold-plated internal and external connectors Subsonic filter eliminates low frequency rumble (less than 17 Hz) caused by mechanical vibration Switchable 15 dB pad for handling extremely high sound pressure levels (SPLs) 3-position switchable pad (0 dB, 15 dB, and 25 dB) for handling extremely high sound pressure levels (SPLs) 3-position switchable low-frequency filter reduces background noise and counteracts proximity effect Cardioid polar pattern, ultra-thin diaphragm, transformerless preamplifier circuitry. Switchable pad (25dB, 15dB) for very high input SPL sources. Class A, discrete, transformerless preamplifier for transparency, extremely fast transient response, no crossover distortion Low self-noise and extended frequency response. Three-position switchable low-frequency filter reduces background noise and counteracts proximity effect Cardioid polar pattern, ultra-thin diaphragm, transformerless preamplifier circuitry Switchable pad (25dB, 15dB) for very high input SPL sources Class A, discrete, transformerless preamplifier for transparency, extremely fast transient response, no crossover distortion