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 : Electronics
JBL Power P1220D 12" Dual 2-ohm Component Subwoofer at Crutchfield