Feature●Nominal Impedance: 8 ohms / DCR: 6 Ohms●Overall Diaphragm Diameter: 3.31" (84.1mm) / Voice Coil Diameter: 1.75" (44.4mm)●This Is A Brand New Aftermarket Replacement Diaphragm.Description This Is A Brand New Aftermarket BMS 4552ND Replacement Diaphragm 8 ohms