Planet Audio Car Subwoofer Series "Torque", Model "TQ12S" | 12 inch, Single 4 Ohm Voice Coil, 1500 Watts Resonant Frequency 35 Hz, Sensitivity SPL (1W / 1m) 87 dB Treated Paper Cone, 2 Inch Aluminum Voice Coil, Foam Surround Sealed Enclosure Internal Volume: 1.1 Cubic Feet, Ported Enclosure Internal Volume: 1.7 Cubic Feet 4 Inch Round Port Circumference, 12 Inch Port Length, 34 Hz Port Frequency 5.2 Inch Mounting Depth, 11 Inch Mounting Hole Diameter Dimensions: Depth 13 x Width 13 x Height 5.8 3 Year Platinum Online Dealer Warranty valid only on products Sold / Shipped by Amazon.com. This offer is not valid on purchases made from third party market place sellers