Shure SM81-LC Cardioid Condenser Instrument Microphone for Guitar, Piano, and Cymbals, Includes Swivel Adapter, Attenuator-Switch Lock, Windscreen, Carrying Case, No Cable Included (SM81-LC)This microphone requires phantom power and performs best with a 48 Vdc supply (IEC-61938). However, it will operate with slightly decreased headroom and sensitivity with supplies as low as 11 Vdc. Most modern mixers provide phantom power. You must use a balanced microphone cable: XLR-to-XLR or XLR-to-TRS.The SM81 is ruggedly constructed. It operates on phantom power and performs over a wide range of temperatures and humidity conditions. It is furnished with a swivel adapter, attenuator-switch lock, foam windscreen, and case for carrying and storage. Other accessories are available.20 Hz to 20 kHz frequency response. Flat response curve for accurate reproduction of sound sources.Low noise and high output clipping level. Low distortion over a wide range of load impedances.Cardioid polar pattern, uniform with frequency and symmetric about axis, providing maximum rejection and minimum coloration of off-axis sounds.Low RF susceptibility.Selectable low-frequency response: flat, 6 or 18 dB/octave rolloff.