Alpine SWR-1241D 12" Dual 4-ohm Voice Coil Subwoofer at Crutchfield
Alpine SWR-1222D Type-R 12" subwoofer with dual 2-ohm voice coils at Crutchfield
Alpine SWR-1242D Type-R 12" subwoofer with dual 4-ohm voice coils at Crutchfield
Amazon.com: Alpine ALP19-R-W12D2x2wKit Car Audio Type R Dual 2 Ohm 1500 Watt 12" Subwoofers with Sub Install Kit and HA-SWKD Dual Sub Box Install Kit - 16 Screws and Speaker Wire with