Shure SM81-LC Cardioid Condenser Instrument Microphone 0 Hz to 20 kHz frequency response Selectable low-frequency response: flat, 6 or 18 dB/octave roll off Low noise and high output clipping level Cardioid polar pattern, uniform with frequency and symmetric about axis, providing maximum rejection and minimum coloration of off-axis sounds Phantom powering (DIN 45 596 voltages of 12 to 48 Vdc)