Specifications:
Impedance (at 1KHz): 150 +/- 20% ohms
Sensitivity (318 Ear/60mv): 99 +/- 2dB
Frequency Range: 300-3400Hz
Axial Field Intensity (at 1KHz 0dB 1A/M): >= -19db
Radial Field Intensity ((at 1KHz 0dB 1A/M): >= -22db
Dimension: 37.8 x 18.80mm