Redefining the term "party barge", these subwoofers bring real bass sounds to your boat. Designed with UV and salt/fog resistant components for maximum performance in the harsh marine environment. Equipped with Flex-Fit for easy installation and Rockford Fosgate's patented VAST technology for maximum output. These subwoofers are made for free air/infinite baffle applications but will also perform well in a sealed enclosure. 500 watts peak power. 4 ohm. 5.54" mounting depth. 9" mounting diameter.