The Alpine PWE-S8-WRA is a bass upgrade system for 2011-up 4-door Jeep Wranglers that do not have the premium sound system with the factory subwoofer. The system consists of the PWE-S8 Restyle Compact Powered 8-inch Subwoofer, a custom bracket to mount the PWE-S8 under the driver's seat, a subwoofer level knob, and a JK-specific wiring harness for plug-and-play installation. The PWE-S8 is a compact powered 8-inch subwoofer paired with a built-in 120W amplifier, housed together in a cast aluminum enclosure. The PWE-S8 measures just 13.5” L x 9” W x 3” D (at the tallest point) so you can add low, punchy, accurate bass to your JK without taking up usable storage space. The die cast aluminum construction provides durability for ongoing performance, so it's ready to take the bumps, jolts and other challenges you put your JK through. The amplifier produces 120W continuous power and the quad-coil subwoofer delivers 25Hz-152Hz frequency response. The PWE-S8 connects to the sound system through the auto-sensing speaker level inputs which are conveniently located on the side panel. The side panel also gives you access to Phase, Gain, LP Crossover and Remote Sub Level controls for proper sound setup. Mount the separate subwoofer level knob on your dash and use it to easily make bass level adjustments. The PWE-S8-WRA works with an Alpine or aftermarket head unit, or with the factory radio. The PWE-S8-WRA is authorized to be Sold By and Shipped From Amazon. For professional installation, visit the store locator on the Alpine USA website to find an authorized Alpine retailer near you.