Custom-fit ported enclosure is designed specifically for 2014–2018 Chevy Silverado & GMC Sierra Crew Cab trucks. It fits four 8-inch subwoofers perfectly under the rear seat with no modifications required. Featuring a front-firing, single-chamber ported design, it maximizes subwoofer performance while preserving cargo space. Built from premium MDF and engineered in the USA, this enclosure delivers strength, reliability, and a seamless OEM fit. Air Space: 2.6 ft³ Mounting Depth: 8.5"