JBL STADIUM122SSI 12” High Performance 1350 Watts Peak Power Selectable Impedance Car Audio Subwoofer Bundle Combo with Class D 1500 Watts Peak Power Car Audio Mono Amplifier and Amp Wiring Kit - Road Entertainment
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