Unit is a Audio-Technica AT961R condenser boundary microphone.
Specifications:
-Element: Fixed-charge back plate permanently polarized condenser
-Polar Pattern: Half-cardioid
-Frequency Response: 30-20,000 Hz
-Low-requency roll-off: 150 Hz, 6 dB/octave
-Impedance: 200 ohms
-Max input sould level: 130 dB, SPL, 1kHz
-Dynamic range: 103 dB, 1 kHz at max SPL