OEM Frame Style-3/ 4 " 2-Way Component System/ Glass Fiber Sandwich Cone With Nomex Honeycomb Core/ Poly-Urethenane Dust Cap/ SBR Surround And Bimax Spider/ Glass Fiber Reinforced Poly-Carbonate Frame/ Neodymium Ring Style Magnet/ 25mm Voice Coil With High Temp Aluminum Former/ Direct Plug-In To Factory BMW Harness/ In-Line External Crossover/ 4-Ohm Nominal Impedance/ CEA-2031 Compliant/ 75Hz - 20kHz Frequency Response/ 87 dB Sensitivity/ Black Finish