An Aftermarket Replacement PDB752 DIAPHRAGM For PDB752 Driver Specs: Overall Diameter: 5" (127 mm) Voice Coil Diameter: 3" (75.5 mm) Diaphragm Material: Titanium Nominal Impedance: 8 ohms DCR: 6 ohms Most Orders Placed Before 2PM and Paid thru PayPal Are Shipped The Same Day; Monday to Friday.