This is a high quality 8 ohm aftermarket diaphragm that fits for many B&C drivers that are used in EAW speaker cabinets and many others speaker 

Specs:
Overall Diameter:  4.31″ (109.5 mm)
Voice Coil Diameter:  2.93″ (74.46 mm)
Diaphragm Material:  Titanium
Diaphragm Height:  14 mm
Diaphragm Thickness:  .05 mm
Nominal Impedance:  8 ohms