Stinger TXTRB10 Underseat 10-inch Subwoofer Enclosure For Full-size Trucks And Other Vehicles - Built tough and made to ?t many under-seat truck installations, this 10” bass enclosure offers a quick and easy way to add a high-powered subwoofer solution to your audio system. Phoenix Gold designed a subwoofer specifically for this enclosure to maximize the performance and deliver deep, accurate bass. Want more output? Add a bass expansion module that adds the correct airspace and a 37-Hz tuned port that gives you over 6-dB of extended bass; that’s like adding another subwoofer! The enclosure also works well behind seats as a footrest, over-center humps, and in hatchbacks. Extreme Bass Push your trucks audio to the limit. Engineered to overcome the lack of space hurdle and adds BIG BASS in trucks where space is a premium. Save-Saving Fit Add some more bass to that wasted space. The enclosure works well behind seats as a footrest, over-center humps, and in hatchbacks. Weather-Resistant Designed to withstand harsh outside elements including water, dirt, dust and debris. Stinger TXTRB10BB Add-on Extention Port For 10-inch Subwoofer Enclosure For Full-size Trucks And Other Vehicles - FOR SILVERADO/SIERRA/DENALI 2007-2019, F150 1999-2020, TUNDRA DOUBLE CAB 2018-2020, AND MORE Double the output! Add this optional modular port enclosure for an extra 6dB bass extension to your TXTRB10 subwoofer enclosure. Features: Roadkill-Armor Coat Permanent Heat Bonded EPM enclosure coating (Elastomeric Polyurethane Molecule) Weather-Resistant for harsh outdoor environments Bundle also includes one Creative Audio Coozy and one 4-piece set of plastic pry tools.