The Prime 12" woofers offer Rockford Fosgate performance at an unbelievable value. These models feature solid stamped steel frame, quick-release compression terminals, and a parabolic polypropylene cone. Best of all, they work great in sealed enclosures. Type: Subwoofers Cone Material: Parabolic polypropylene cone Voice Coil: Single Voice Coil Construction: 2.0" (4-Layer) Gasket: Stamped steel basket RMS Power: 150W Sensitivity: 87 dB Impedance: 4 Ohm