Alpine 12” Type R-Series Powered Ported Bass Package Includes one Alpine R-W12D4 12” subwoofer, R-A75M amplifier, and 2.25 ft³ optimized ported enclosure
Alpine S-Series 12" Dual-Voice-Coil 4-ohm Subwoofer Black S-W12D4 - Best Buy
Alpine Jeep Wrangler Single 12-Inch Alpine Halo R-Series Preloaded Subwoofer Enclosure with ProLink R2-SB12V (Universal; Some Adaptation May Be Required) - Free Shipping
Alpine W12S4 - BassLine Series Subwoofer by Alpine. 12" 4-ohm - Car bass sub-woofers - Custom Sounds & Tint
Alpine SWR-1222D Type-R 12" subwoofer with dual 2-ohm voice coils at Crutchfield
Amazon.com: Alpine S-W12D2 Car Audio Type S Dual 2 Ohm 1200 Watt 12" Subwoofers with Sub Install Kit Package : Electronics