Alpine SWR-1242D Type-R 12" subwoofer with dual 4-ohm voice coils at Crutchfield
Alpine Type-E SWE-1042 1-Way 10in. Car Subwoofer for sale online | eBay
Universal Car Stereo Slotted S Port Single 10" Alpine Bundle Type R R-W10D4 Sub Box Enclosure with Harmony HA-A800.1 Amplifier & 4GA Amp Kit - Walmart.com