Polk Audio PSW125 12-Inch Powered Subwoofer (Single, Black) 12" Composite Bass Driver Delivers Deep, Powerful Bass 150w Continuous/300w Dynamic Power Amp Slot-loaded Vent Improves Bass Response With Lower Distortion Line Level & Speaker Level Inputs Auto On/off Saves Energy When Not In Use A single 12-inch subwoofer with compression circuitry to limit distortion at earth-shaking volume levels Equipped with one 12-inch dynamic balance composite woofer driver Features laser-based Klippel measurement technology for improved linearity and deep, precise sound Frequency Response: 32Hz - 225Hz; Peak power handling: 300 watts (150 watts continuous) The item is non-returnable.