Powder Coated Cast Aluminum Frame – to withstand extreme environmental use. Injection Molded Composite Cone – For durability & low distortion. Rubber Spider – Much more durable to water & temperature changes than a traditional treated Cotton Spider used by the majority of marine speakers & subwoofers. Rubber Surround – Offers a superior bond to the composite cone. Gold Plated Terminals – Designed to resist corrosion. Impedance: 4 ohms RMS Watts: 500 PEAK Watts: 1000 Frequency Response: 20Hz to 400HZ Sensitivity: 88 db at 1watt/1 meter Weight: 17.6 lbs (7.98kg) Diameter: 12.6 inches (320.04mm) Mounting Depth: 4.92 inches (124.96mm) Hole Cut Out: 11.26 inches (286.00mm) Vented Enclosure: Min 1.1 cu ft sealed or 1.7 cu ft (Optimum: Tuned at 41 Hz) ported Grills Sold Separately | Wet Sounds | | REVO 12 High Power S4-B Black 12 Inch 4 Ohm Subwoofer, No Grille | Black/Gray | Best Buy