JBL BassPro 12 | 12" (300mm) Car Audio Powered Subwoofer System with Slipstream Port Technology
Amazon.com: JBL Club WS1200 12" Shallow Mount subwoofer w/SSI (Selectable Smart Impedance) Switch from 2 to 4 ohm Bundled with Alphasonik Earbuds : Electronics
JBL Club 1224 Club Series 12" component subwoofer with switchable 2- or 4-ohm impedance at Crutchfield
JBL Grand Touring Series GTO1204D 12" subwoofer with dual 4-ohm voice coils at Crutchfield