Best Buy: Alpine Type-R 12" 1000W Subwoofer Black SWR-12D4
Alpine SWR-1242D Type-R 12" subwoofer with dual 4-ohm voice coils at Crutchfield
Amazon.com: Alpine Type R 12 Inch 2250 Watt Max 4 Ohm Round Car Audio Subwoofer %7C R%2DW12D4 : Electronics
FS: Alpine Type R 12" sub + JBL BP300.2 mono amp - BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)
Alpine SWR-1242D (SWR1242D) 12" Dual 4 ohm Type-R Car Subwoofer
2) Alpine Type R 12 Inch 2250 Watt Max 4 Ohm Round Car Audio Subwoofer - Walmart.com