This is a combination ribbon and moving coil microphone made by the American Microphone Company of Pasadena, California. Frequency response is from 40 to 15,000 hertz, with an output level of –86 dB. Polar patterns are cardioid (ribbon and moving coil), bi-directional (ribbon only), or omni-directional (moving coil only). Impedance is switchable for 50, 150, or 250 ohms. Dimensions are six inches high and two inches in diameter. Weight is twenty ounces.