The Shure SM137 is a versatile, flat-response cardioid condenser instrument microphone with an ultra-thin diaphragm for a frequency response that combines a smooth high-end with a tight, controlled low-end. It boasts a 15db pad for natural sound reproduction in both acoustic and high volume performance applications. Ultra-thin diaphragm for smooth high end and tight, controlled low end 15dB pad for performance consistency across a wider range of high SPL sources Low self-noise and transformerless preamplifier circuitry