Type 4966-H-041 is designed for high-precision, free-field measurements where a microphone with high sensitivity is required. Precision sound measurementPremium class sound level metersElectroacoustic measurement  Capacitance: 14 pF Diameter: Dynamic range: 16.5 134 dB Frequency range: 6.3 20000 Hz Inherent noise: 16.5 dB A Lower limiting frequency -3dB: 3 Hz Optimised: Free field Polarization: Prepolarized Polarization voltages: 0V Pressure coefficient: -0.01 dBkPa Sensitivity: 50 mVPa Temperature coefficient: 0.