perhaps http://www.primo.com.sg/products.html ?
No actually its this link,
http://www.primomic.com/These are the capsules I use for my pro binaural mics. EM-123
Small size
High reliability
Suitable for ultra sound application to 40KHz
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Type Electret Condenser
Directional Non-Directional
Sensitivity -43dB@1KHz (0dB=1V/ Pa) RL=2K ohms, Vcc=3V
Operating Voltage 3V (1.1V~10V)
S/N Ratio 58db
Circuit Current 400µ A max (Vcc=3V)
Impedance 1.6K ohms (1KHz)
Max Input S.P.L. 120db S.P.L.
Weight 0.2g