High Quality Driver NC-72:
Throat diameter: 2" (50mm)
Mounting type: bolt-on
Nominal impedance: 8 ohms
Power rating: 120 watts
RMS Sensitivity: 112 dB
Frequency response:  800-16kHz
Recommended crossover: 1.0kHz or higher(12dB/oct.minimum)
Diaphragm material: titanium 
Voice coil: 2.84"(72.2mm) ,polyimide film,CCAW winding
Magnet weight:  70 oz(ferrite)