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: 400 PEAK Watts: 800 Frequency Response: 20Hz to 400HZ Sensitivity: 88 db at 1watt/1 meter Weight: 17.6 lbs (7.98kg) Diameter: 11.02 inches w/grill (279.90mm) (sold separately) Mounting Depth: 4.72 inches (119.88mm) Hole Cut Out: 9.45 inches (240.03mm) Vented Enclosure: Min 1.0 cu ft sealed enclosure or 1.3 cu ft ported Grills Sold Separately