JZ Microphones BT-301, Mid-Size Condenser Microphone, Transducer type:electrostatic condenser, Operating principal: pressure gradient, Diaphragms active diameter: 21mm, Frequency range: 20 Hz to 20 kHz, Polar pattern: Cardioid, Output impedance: 50 ohms, Rated load impedance: 1000 ohms, Suggested load impedance: >500 ohms, Sensitivity at 1000 Hz into 1000 ohms load: 33mV/Pa, S/N Ratio CCIR 468-3 weighted: 76 dB, S/N Ratio DIN/IEC 651 A-weighted: 87 db-A, Equivalent noise level DIN/IEC A-weighted: 5,5 dB-A, Maximum SPL for 0.5% THD at 1000 ohm load: 133,5 dB, Dynamic range of the microphone preamplifier: 128 db, Phantom powering voltage on pins 2 & 3 of XLR: +48 V (+/-4 V), Current consumption: < 2 mA, Output connector: 3-pin XLR male, gold plated contacts, Signal polarity: positive toward pressure on a diaphragm produces positive polarity voltage on XLR pin #2 relatively to pin #3