The SM137 has an ultra-thin diaphragm for a frequency response that combines a smooth high-end with a tight, controlled low-end and a 15db pad for natural sound reproduction in both acoustic and high volume performance applications. Low self-noise and transformerless preamplifier circuitry. Output: 3-Pin XLR Frequency response: 20 Hz - 20 kHz. Length: 162 mm. Diameter: 24 mm. Weight: 196 g.