Powerbass S12T 12-Inch Single 4 Ohm Thin Subwoofer Thin mount woofer design - fiber composite Turbine basket Single piece custom injected molded cone - large roll rubber Surround Oversized motor structure - Dual and single 4-Ohm voice coils 2" vented ksv voice coil former - chrome push terminals Optimally designed for small sealed enclosures