2) Polk Audio DB1042SVC 10” 1050w Single 4-Ohm Car/Marine Audio Subwoofers Subs - Walmart.com
MM1042 DVC 10" Subwoofer, Car & Marine | Polk Audio
M6-880ETXv3-Sb-S-GmTi-i - Marine Audio - Enclosed Systems - Enclosed Speaker Systems - ETXv3 - M6 – JL Audio
BOSS Audio Systems P80DVC Phantom Series 8 Inch Car Audio Subwoofer - 100 Watts Max, Dual 4 Ohm Voice Coil, Sold Individually, For Truck, Boxes and Enclosures, Use With Amplifier
Marine Audio - Subwoofers - Wet Sounds
Kicker 45KMF104 10" 4-ohm marine subwoofer — optimized for free-air applications at Crutchfield
Amazon.com: (2) Polk Audio DB1042DVC 10 1050 Watt Dual 4-Ohm Car/Marine Audio Subwoofer Sub Bundle with Dual Sub Box Enclosure Installation Kit and Rockville RD10 Dual MDF Sealed Subwoofer Enclosure (4 Items) : Electronics
Wet Sounds Stealth AS-10 Marine powered subwoofer — sealed enclosure with 10" sub and 500-watt amplifier at Crutchfield
Polk Audio DB842DVC DB+ Series 8 Inch Dual Voice Coil Shallow Subwoofer with Marine Certification